ECO 231W

Undergraduate Econometrics

Handing the Project

You must hand the project on Friday 12/11 at 5 pm at Harkness 116G. The project TA Cristian will stay there until 5:45 pm. Notice that the due time is 5 pm, so Cristian will stay there longer only as a courtesy. If you arrive after 5:45 pm you may not find him anymore, you will have missed the deadline and severe penalties will apply.

The Final

The Final exam is, as you probably know, on Wednesday 12/16. To find the place and time, look in the calendar page.

The final has one material question, and one essay question. The material question is in the same style as in the midterms. In fact, most items will be the same or similar to the ones in the previous midterms. I may come up with a new question or two, but the previous midterms are really the best guide. I have no intention of surprising you. The material question is worth 70% of the exam grade.

The essay question gives you either a topic, or sometimes a specific research question. You are supposed to write how you would go about doing research on that topic. You can find examples of essay questions in the previous finals I published in the
downloads page. The essay question is worth 30% of the exam grade. Here I give you more details and guidance which may be useful in preparing for the essay question in the exam.

Content: you must explain things in a fair amount of detail. For example, what would you be looking for on a data sets, and which problems do you expect to encounter? You must be specific. “I will check for measurement error in the most important variables” is better than not saying anything, but I’m really looking for “I am expecting a possible measurement error in ***, because of ***. I will try to establish if this is indeed the case by *** (describe action you will take, which can involve looking in the data, in the questionnaire, in the codebook, in another data set [what kind], in the literature [which literature]. You must think about it in the specific case). How will you try to solve it? Can you? How? Do you anticipate it will be basically impossible? What will you do in this case? Which bias do you expect?

Structure: I suggest that you prepare a clear essay structure in advance, where you are sure you will cover every aspect you must discuss in an organized manner. Give the matters their due importance. You are not repeating the last class, you are adapting it to an actual situation. For example, I told you there that you should check for sample selection at a certain point. It was just quick reminder. However, you must discuss this in some detail in the situation, give it a separate paragraph. Which type of sample selection? How do you suppose you will find that out in this specific case? What will you do, etc.

Style: there is no restriction to the size of the essay. We can’t avoid this: flow, style and grammar matter. We don’t particularly reward those, but indirectly we do. We do specifically reward the organization and clarity of your arguments.


I know that you must feel overwhelmed, and also perhaps scared at not knowing what will come. Don’t think this way, because it is not true. The final is not that different from the midterms, and you can prepare very well using those. The essay is in the same style: you know what to expect, you just don’t know the situation. Take a moment to appreciate the fact that although this course was indeed a lot of work, you can answer a question about how you would go about doing a research project on your own. One semester ago you would not be able to even start answering this question, and now you can go all the way in detail. In spite of all the worry about grades that fill your mind most of the time, try to find some satisfaction in what you actually learned: no grade, no bad day, no bad luck is going to take this away from you. Good luck, though luck is hardly necessary.

Further project consultation meetings

You can now sign up for up to two more slots to meet with the Project TA. Remember: only your earliest meeting counts for extra points.

If you haven’t signed up for any meeting yet, you should do this soon. If we run out of slots you will not be able to take advantage of this resource and the free points. Even of someone else has 3 meetings scheduled and you have none, we will not open further slots to accommodate you.

No class on Thanksgiving week

In case you have not noticed this in the class plan, we have no classes on Thanksgiving week. Have a great break!

Midtem 2 answers published

I just published the exam answers. You can find them in the downloads page.

Project Consultation Meetings

It is time to start thinking about the final project. Don’t worry, you can have your rest next week, but you have to give this topic a bit of thought. To incentivize this, and also to help you form your project idea, we will be offering a special set of meetings. Here is how they work:

From Monday 11/30 until Friday 12/04, the project TA (Cristian) will be holding special consultation meetings. The meetings are 10 minutes long, but you should leave about 20 minutes open for this activity.

The meetings are individual. You will bring your idea about which critique point you will pursue for the project, and the strategy you are planning (evidence you are intending to use, data sets you plan to explore, etc.) to the meeting. Cristian will hear you out, and help you as much as he can given how much you prepared, and the path you decided to take. In some cases, he may tell you that your idea is not very good, so you should pursue another, or he may help you modify or refine the idea you are already thinking of defending. Use the project instructions that I published in the previous announcement as a guide for choosing your idea.

The meetings are not mandatory. However, we want to incentivize you to come. The project is worth 100 points. If you simply show up to a meeting, you will get 1 point over your final project grade. Then, depending on how prepared you are for the meeting (quality of the idea, how much you thought about the evidence sources, etc.) you can get up to 5 points over the project grade.

Sign up for meetings using
this link. Right now you can sign up for only one meeting. If we see two appointments from you we will cancel both without warning. However, starting Monday 11/30 you can sign up for up to two further meetings if you would like to get more help. Only your earliest meeting counts for extra points. Once we run out of slots this is it, so sign up soon if you want to make sure you take advantage of this resource.

If you want to reschedule your appointment, cancel the one you already have, and then make a new one. You can cancel your appointment up to 24 hours in advance. You can schedule an appointment up to 6 hours in advance. If you miss your appointment without having cancelled it, you can schedule a new appointment, but you will not receive the bonus points. Contact the Project TA if you have questions about the appointments.

You must check in at HARK 207 at or before your scheduled meeting time.

The Final Project

The project is due on 12/11/15. See details about the time and location where you will hand it in the calendar page. It must be handed in paper (print and staple it).

The final project is a critique of this semester’s paper. The critique will be based in 1 point. It means that, although you may know several things that are wrong with the paper, your project will discuss only one. Of course, choose the best one you can.

The project begins with an introduction, where you explain the paper in broad lines: the question, the methodology, the results, and the conclusion. Then you introduce the point which will be the basis of your critique. You have to explain what your point is, then you have to provide evidence for this point, and finally you have to describe the consequences for the results of overlooking your critique point. For example, if you are defending that there is an omitted variable, you must explain what is the consequence of this omission: is the bias positive or negative? What is the consequence of this for society? Finally, you must have a conclusion. Don’t forget the bibliography, if applicable. It must follow a standard academic style. Any style is fine, as long as it is the same for all entries. Turabian (also known as Chicago style) is a good choice, very well accepted in Social Sciences.

The critique point must be specific. Is it omitted variable bias? Then you must defend that 1 specific variable was omitted. Which is it? Is it measurement error? Then which variable has measurement error? Is it sample selection? Then are you concerned with selection in which specific way? You must provide evidence, and you can go as far as you want there. You can use pure logic, you can use newspaper sources. However, the royal evidence comes from actual research papers. If you want to really impress, you can bring outside datasets. There is no limit to the creativity you can put into the evidence for your point. Moreover, if you can solve the problem, then you should. It is not necessary to do this, and historically only 2 students per year manage to provide full solutions to the problems they suggest, but it certainly increases the level of impressiveness of your project to a whole new level.

The project has strict formatting rules. The paper cannot have more than 10 pages counting everything (except the cover page). It must be written in single-space, Times New Roman font size 12. The document must leave 1 inch of space in all margins, no more, no less. Pages must be numbered. Include a cover page with your name, student ID, and class time. Don’t try to fumble with the editing rules, because we have way too many examples to compare. You have a bit of freedom within reason in how you format and space the section titles, as well as figures and tables, if you have some. Here are some guidelines (not obligatory) to help you write the paper: a typical critique has a 2 page long introduction, then the critique itself is introduced in general lines in about half a page. The body of the critique is very free, and the conclusion is usually at most one page long.

The project is graded based on many things. First, the introduction where you summarize the paper. There we are looking for an excellent understanding of what truly matters in this year’s paper. The words about which you should think are conciseness, precision, and readability. To help you write this section, read question 2 in all midterms again. Many items there were designed to make you extract the essence of the paper arguments in a few lines.

The body of the paper is, of course, the most important part. We are looking for a good critique point, which is defended using excellent evidence. The critique must clearly delineate what are the consequences of the problem you are raising. We reward creativity very highly. You can defend the same critique point as many of your colleagues, but then you are in direct comparison with them. If you choose an unexplored critique point, you will be evaluated on your own, which is a good thing. Moreover, when we see a novel critique point, we imagine that you thought about, but rejected, several more common ideas. Hence, we will reward you directly. We also reward the quality of the evidence. Not all evidence has the same strength and reliability. It goes like this: straight from data>>research papers>>online verifiable journalistic sources>>logical argument. This is not written in stone, but it’s a decent guideline. We reward effort and creativity involved in choosing, searching, and using the evidence. We also reward the strength of your whole argument. Is it easy to understand? Are you convincing?

You can make up for things. For example, you may not be defending the most creative critique point, but you can make up for it with a brilliant evidence source, or even (wow!) a direct solution. Additionally, this is an essay, so your language counts a lot. We establish just a few points for style and grammar, but don’t underestimate the power of a well written piece. An argument that develops fluidly, a paper that is not boring, a paragraph that is so well structured that the mind just cruises through it, all of those end up reflecting on your final grade. We punish pretty severely when your arguments are not clear, when we have to re-read things many times to get the point.

This project is not about doing everything right. Your paper may defend a correct critique point, use good evidence, and be sufficiently clear, and it will still not garner the maximum grade. You can always choose to break free from mediocrity. You can choose to be ambitious, to risk, and we will reward that.

Final note: you can get help with grammar and style. Check out this link to the
College Writing Program. They can read your essay over, they can help edit it. You should take advantage of this resource, it will serve you well for when you are writing other essays in the future. Do you see how journalists write? This style is very persuasive. I’ve seen students that could write this smoothly, and we couldn’t help but give them a better grade. Never underestimate the importance of presentation, be it in person or in paper.

Some clarifications about the Midterm 2

Here are two clarifications about two exam questions:

2.c) The “college major control” to which that question refers is the mathematical content of each college major. From the paper:
"Two different college major controls were used. The first is the standard set of dummy variables for individual college majors. The second college major control is a single variable, the mathematical content of each college major.”

2.k) Although the question asks you to interpret beta_8, we are not looking for the formal interpretation. Rather we are looking for an explanation about which is the likely sign of this coefficient and why.

Grading office hours postponed

The grading of the replication is taking longer than predicted. You should be receiving your grades tomorrow. For this reason, the grading office hours for the replication will happen next week. Check the calendar to see the time and location (which will be the same as always).

Midterm 2 preparation

Midterm 2 preparation is published in the download page.

This document has all the questions that will be in the actual midterm, with 2 differences: (1) the Material Question will have an actual situation, with real variables like class attendance and smoking. The preparation has generic variables like y and x
1. (2) In the midterm you will only receive a subset of these questions, so that you have time to answer them.

If you want to know more about the intentions behind the midterm and how to prepare, read
this.

The midterm will take place in the regular classroom in the regular class time. You should plan around 1 to 1:05 hour to write your answers.

I will give you one booklet with the questions, and two other booklets, one for the Material Question, and one for the Paper Question. These booklets have space for answering each of the items. Since the answer space of each question is set, you don’t need to write the answers in a row. You can write the bulk of the answers to all questions, and if you have extra time you may go back and complete them with extra flourishes.

Replicatuion Dataset Published

Find it in the Downloads page.

Replication

You will replicate the project paper (the same one of question 2 in the Midterm). This means that you will get the data and clean it according to the descriptions in the paper. You can find the data and the codebook in the Download page. Then you will generate the same variables that the authors say they do, and run the same regressions. Finally, you will make sure that your code presents all the values in the table in a format that is very easy to see. You need to reproduce Tables 1 and 2.

The code must be clean and organized. You have a good measure of freedom in deciding how you will organize your code. The point is to use comments to create sections for each different part of the replication. You should also use comments to explain what the commands are doing. The way you should approach this is as someone who is writing a code that will be used by others. Could they run it if they had the same data set? Could they understand it with minimum effort?

As with the homeworks, this assignment is a .do file. One .do file. You are graded on the correctness of what you did, on how close you get to the results, on how clean and elegant is your code, and on how easy it is to understand. Think that you are working with a coauthor, or with colleagues in a company. You don’t want to explain so much that it is tiresome to read, but you must make sure that the reader doesn’t spend time figuring out what you intended with this or that command.

The replication is usually a challenging assignment. The hard truth is that you can very seldom replicate exactly the same results of a paper. Sometimes papers have mistakes, but even when they don’t, the authors may have done something with the data that they didn’t describe in the paper, perhaps by distraction, perhaps intentionally. So, you won’t get the same results that they did. How close can you get? As you try to figure this out you will gain a very deep understanding of the paper.

Usually this process is very time consuming. Don’t play with this, you never replicated a paper before, you don’t know what it is like. You will run into coding problems, you may need to learn a Stata trick, you may have to start again. Even when you get it to run, you may not be getting results that are close enough, what are you doing differently? You will need time to go to office hours and experiment until you figure it out.

Alon is the specialist in the replication. The undergrad TAs have done replications of their own when they took this course, so they can help as well. However, on this particular assignment, try to get Alon’s help if you can.

The replication is due on Friday 11/06 at 5:00 pm. You must upload the replication file in the upload page. For details on how to upload it, read this. The password is still the same as for the homeworks. The replication is graded out of 10 points, and it is worth 10% of the grade.
 

PENALTIES IF THE FILE DOESN’T RUN
If your .do file doesn’t run, the TA will request that you fix it, and give you a deadline (usually until the next day). Each time he has to request a correction for the file to run, you lose 2 points. If you fail to make the deadline of a correction request, your replication won’t be accepted anymore. You choose which email we will use to contact you when you upload the file. Make sure that it is one you check often.

LATENESS PENALTIES
Every hour past the due time, your replication loses 10 points. Here is a breakdown:

Received before 5:00 pm until 5:59: no penalty
Received between 6:00 and 6:59: -2
Received between 7:00 and 7:59: -4


and so on until 10 pm, at which time we will not accept your replication any longer. Read the policy on late assignments here.

NOTICE: the replication is due before or at 5:00 pm. We only start discounting points at 6:00 pm to allow for internet delays, browser reloading or any other unpleasant things that may happen. We will not accept any excuse related to technology. If you can’t rely on your connection, or your browser, then take measures to upload your homework earlier, or even better, the night before.

Think that there are way too many rules to follow in this course? Read this.

Problem in Notes 12

I updated the notes, so now you can have the correct one. If you want to keep your old version, just cut page 2, and add at the end about half a page of the material from the end of the updated notes, beginning with “So, if we want to be 95% confident, the formula of our interval is: ...”

Typo on Homework 2

There was a typo in question 1(b) which asked about a regression you ran in part (a) of question 1, not part (k) as previously written. I have corrected it now.

Homework 2 is posted

You can find homework 2 in the download page.

Homework 1 is due on Friday 10/23 at 5:00 pm. You must upload the homework file in the
upload page. For details on how to upload your homework, read this. The password is the same that you used for homework 1. Consult your notes from 9/21, ask your classmates or email Alon if you forgot.

Your homework is a .do file (
ONE .do file!). For details about what is, and how to produce a .do file for your homework, read this (but more importantly, watch the Stata videos or come to the recitations). Find the data sets in the download page, unless specified in the homework.

PENALTIES IF THE FILE DOESN’T RUN

If your .do file doesn’t run, the TA will request that you fix it, and give you a deadline (usually until the next day). Each time he has to request a correction for the file to run, you lose 2 points. If you fail to make the deadline of a correction request, your homework won’t be accepted anymore. You choose which email we will use to contact you when you upload the file. Make sure that it is one that you check often.

LATENESS PENALTIES

Every hour past the due time, your homework loses 2 points. Here is a breakdown:

Received before 5:00 until 5:59: no penalty
Received between 6:00 and 6:59: -2
Received between 7:00 and 7:59: -4


and so on until 10 pm, at which time we will not accept your homework any longer. Read the policy on late homeworks
here.

NOTICE: the homework is due before or at 5:00 pm. We only start discounting points at 6:00 pm to allow for internet delays, browser reloading or any other unpleasant things that may happen. We will not accept any excuse related to technology. If you can’t rely on your connection, or your browser, then take measures to upload your homework earlier, or even better, the night before.

Think that there are way too many rules to follow in this course? Read
this.

Midterm 1 answers published

I just published the exam answers. You can find them in the downloads page.

Midterm 1 rephrasing

I noticed that some students were confused about a few items because of the phrasing, so I rephrased some of the questions. Check the exam questions 2.j, 2.k and 2.n and see if it makes things clearer.

Midterm 1 preparation

Midterm 1 preparation is published in the download page.

This document has all the questions that will be in the actual midterm, with 2 differences: (1) the Material Question will have an actual situation, with real variables like class attendance and smoking. The preparation has generic variables like y and x
1. (2) In the midterm you will only receive a subset of these questions, so that you have time to answer them.

The paper question refers to the project paper, which can be found in the
Downloads page. The paper will not be given to you during the exam, nor are you allowed to bring it with you. However, if the question refers to a table in the paper, I will include a copy of the table in the exam.

If you want to know more about the intentions behind the midterm and how to prepare, read
this.

The midterm will take place in the regular classroom in the regular class time. You should plan around 1 to 1:05 hour to write your answers.

I will give you one booklet with the questions, and two other booklets, one for the Material Question, and one for the Paper Question. These booklets have space for answering each of the items. Since the answer space of each question is set, you don’t need to write the answers in a row. You can write the bulk of the answers to all questions, and if you have extra time you may go back and complete them with extra flourishes.

No class on Wednesday

Remember that there will be no class on Wednesday 09/23.

Another typo on Homework 1

There was a typo in question 5. part (j) asks about a graph you drew in part (i) of question 5, not part (h) as previously written. I have corrected it.

Typo on Homework 1

There was a typo in question 5. The file you will need to use is CAS2001.dta , and not CAS2011.dta. I have corrected it. The file is available for download on the Download page.

About the .do files

Your homework is 1 .do file. Even if the homework has several questions, you must write 1 .do file that answers all. Make sure that you read the FAQ question about the .do files linked here. Also, to minimize the likelihood that your file does not run, always:

1. make sure to use the 'clear' command before using any data set in your do-files so that any previous data in STATA's memory can be cleared away.
2. with the 'use' command don't give in the entire path name of the data set, just write, use GPA2.dta, for example. You can set the home directory separately using 'cd'. The TA will then change the path and run the entire file without any problem.

Remember, you lose points if the file does not run on another person’s computer, so be careful with that. Ask any of the TAs if you have questions about that, especially the Stata TAs.

Homework 1 is posted

You can find homework 1 in the download page, where you can also find the data set needed to answer one of the questions, as well as the Stata videos. The homework covers up to and including video 7.

Homework 1 is due on Friday 09/25 at 5:00 pm. You must upload the homework file in the
upload page. For details on how to upload your homework, read this. You will need a password, which I will give out during class on 09/21 (if you miss class that day, find out the password from your classmates or email Alon on or after 09/21.)

Your homework is a .do file (
ONE .do file!). For details about what is, and how to produce a .do file for your homework, read this (but more importantly, watch the Stata videos or come to the recitations). Find the data sets in the download page, unless specified in the homework.

PENALTIES IF THE FILE DOESN’T RUN

If your .do file doesn’t run, the TA will request that you fix it, and give you a deadline (usually until the next day). Each time he has to request a correction for the file to run, you lose 1 point (in the following homework you lose 2 points). If you fail to make the deadline of a correction request, your homework won’t be accepted anymore. You choose which email we will use to contact you when you upload the file. Make sure that it is one that you check often.

LATENESS PENALTIES

Every hour past the due time, your homework loses 2 points. Here is a breakdown:

Received before 5:00 until 5:59: no penalty
Received between 6:00 and 6:59: -2
Received between 7:00 and 7:59: -4


and so on until 10 pm, at which time we will not accept your homework any longer. Read the policy on late homeworks
here.

NOTICE: the homework is due before or at 5:00 pm. We only start discounting points at 6:00 pm to allow for internet delays, browser reloading or any other unpleasant things that may happen. We will not accept any excuse related to technology. If you can’t rely on your connection, or your browser, then take measures to upload your homework earlier, or even better, the night before.

Think that there are way too many rules to follow in this course? Read
this.

Introducing Fall 2015's Paper

The paper we will be using this semester is

Mathematical College Majors and the Gender Gap in Wages

by Catherine J. Weinberger. It was published in 1999 by the journal Industrial Relations.

We will be using this paper in the midterm questions, in the replication, and in the project.

3:25 group room change!

The 3:25-4:40 group class will no longer be at Morey 504. It will now be at Gavett 312.

As we all know, Morey 504 is excessively hot. I requested a change and this is the room they gave us. I don’t know how good it is, but I am hoping that at least we won’t feel like we are in an oven anymore.

Welcome to ECO 231W Fall 2015!

This page contains all the announcements for the course. It is your obligation to keep up with it. Here I post all the rules concerning assignments, and I also let you know if there will be any change. Did you read the Check-in page? That should be your first stop (find the tab at the top of the main page).

The Final

The Final exam is, as you probably know, on the coming Monday and Tuesday. To find the place and time, look in the calendar page.

The final has one material question, and one essay question. The material question is in the same style as in the midterms. In fact, most items will be the same or similar to the ones in the previous midterms. I may come up with a new question or two, but the previous midterms are really the best guide. I have no intention of surprising you. The material question is worth 70% of the exam grade.

The essay question gives you either a topic, or sometimes a specific research question. You are supposed to write how you would go about doing research on that topic. You can find examples of essay questions in the previous finals I published in the
downloads page. The essay question is worth 30% of the exam grade. Here I give you more details and guidance which may be useful in preparing for the essay question in the exam.

Content: you must explain things in a fair amount of detail. For example, what would you be looking for on a data sets, and which problems do you expect to encounter? You must be specific. “I will check for measurement error in the most important variables” is better than not saying anything, but I’m really looking for “I am expecting a possible measurement error in ***, because of ***. I will try to establish if this is indeed the case by *** (describe action you will take, which can involve looking in the data, in the questionnaire, in the codebook, in another data set [what kind], in the literature [which literature]. You must think about it in the specific case). How will you try to solve it? Can you? How? Do you anticipate it will be basically impossible? What will you do in this case? Which bias do you expect?

Structure: I suggest that you prepare a clear essay structure in advance, where you are sure you will cover every aspect you must discuss in an organized manner. Give the matters their due importance. You are not repeating the last class, you are adapting it to an actual situation. For example, I told you there that you should check for sample selection at a certain point. It was just quick reminder. However, you must discuss this in some detail in the situation, give it a separate paragraph. Which type of sample selection? How do you suppose you will find that out in this specific case? What will you do, etc.

Style: there is no restriction to the size of the essay. We can’t avoid this: flow, style and grammar matter. We don’t particularly reward those, but indirectly we do. We do specifically reward the organization and clarity of your arguments.


I know that you must feel overwhelmed, and also perhaps scared at not knowing what will come. Don’t think this way, because it is not true. The final is not that different from the midterms, and you can prepare very well using those. The essay is in the same style: you know what to expect, you just don’t know the situation. Take a moment to appreciate the fact that although this course was indeed a lot of work, you can answer a question about how you would go about doing a research project on your own. One semester ago you would not be able to even start answering this question, and now you can go all the way in detail. In spite of all the worry about grades that fill your mind most of the time, try to find some satisfaction in what you actually learned: no grade, no bad day, no bad luck is going to take this away from you. Good luck, though luck is hardly necessary.


How to hand the Project

As you know, we won’t have class on Wednesday. To hand the project, you have to show up at one of the following times and locations:

- Wed 04/29 12:30-12:45 pm at HUTCH 473
- Wed 04/29 3:25-3:40 pm at B&L 109

Notice that you only have a 15 minute window while the TA will be at the room to collect the projects. You can hand your project at any of these times, it does not matter if you normally attend it or not. Someone else may hand the project for you. Make sure that you follow the instructions for formatting, or you may lose points. Make sure that your project is stapled. Good luck!

About sharing material for the project

I would like to clarify that it is ok to help other students with their project. Sharing material consensually is allowed in this course unless I expressly forbid it (for example, I expressly forbid it during the exams, or homework answers in the forum). I am writing this for the following reason: many students did not do so well in the replication. Now they want to do well in the project but need help to run regressions, since their own codes are not great. I want to make sure that all of you know that if you are willing to share your code with another student (or all students, even in the forum) you can do so at this point. Of course, your code belongs to you, and you are in no way required to do this. I also want to remind all students that it is not necessary to have regressions at all in the project. It is possible to write a brilliant piece without touching data at all.

Extra office hours for the project

Olamide, the Project TA, will be holding extra office hours Monday and Tuesday next week. Check the calendar for details.

Exams 3:25-4:40 group

By mistake I brought the leftover exams for the 3:25-4:40 group home with me. I will not be coming to the department until Monday. If you want to know your grade, please email Alon. If you can wait, I will put the exams in the box at Harkness around 2 pm on Monday.

Link for the Project Consultation Meetings

To sign up for a specific time slot, click here.

You can only sign up to one time slot for now. If we have more than one appointment from you, we will cancel both. Later in the week, if we still have plenty of open spaces we will allow you to sign up for further meetings so you can take advantage of the advice from the Project TA. Notice, however, that the extra points will be given only at your first meeting.

If you want to reschedule your appointment, cancel the one you already have, and then make a new one. You can cancel your appointment up to 24 hours in advance. You can schedule an appointment up to 6 hours in advance. If you miss your appointment without having cancelled it, you can schedule a new appointment, but you will not receive the bonus points.
Contact the Project TA if you have questions about the appointments.

Project Consultation Meetings

Now that you handed the replication, it is time to start thinking about the final project. Don’t worry, you can have your rest next week, but you have to give this topic a bit of thought. To incentivize this, and also to help you form your project idea, we will be offering a special set of meetings. Here is how they work:

From Wednesday of this coming week until Tuesday of the next week, the project TA (Olamide) will be holding special consultation meetings. The meetings are 10 minutes long, but you should leave about 20 minutes open for this activity.

The meetings are individual. You will bring your idea about which critique point you will pursue for the project, and the strategy you are planning (evidence you are intending to use, data sets you plan to explore, etc.) to the meeting. Olamide will hear you out, and help you as much as he can given how much you prepared, and the path you decided to take. In some cases, he may tell you that your idea is not very good, so you should pursue another, or he may help you modify or refine the idea you are already thinking of defending. Use the project instructions that I published in the previous announcement as a guide for choosing your idea.

The meetings are not mandatory. However, we want to incentivize you to come. The project is worth 100 points. If you simply show up to a meeting, you will get 1 point over your final project grade. Then, depending on how prepared you are for the meeting (quality of the idea, how much you thought about the evidence sources, etc.) you can get up to 5 points over the project grade. You can only attend 1 meeting.

On Monday evening I will post a link where you will be able to sign up to a specific time slot.

The Final Project

The final project is a critique of this semester’s paper. The critique will be based in 1 point. It means that, although you may know several things that are wrong with the paper, your project will discuss only one. Of course, choose the best one you can.

The project begins with an introduction, where you explain the paper in broad lines: the question, the methodology, the results, and the conclusion. Then you introduce the point which will be the basis of your critique. You have to explain what your point is, then you have to provide evidence for this point, and finally you have to describe the consequences for the results of overlooking your critique point. For example, if you are defending that there is an omitted variable, you must explain what is the consequence of this omission: is the bias positive or negative? What is the consequence of this for society? Finally, you must have a conclusion. Don’t forget the bibliography, if applicable. It must follow a standard academic style. Any style is fine, as long as it is the same for all entries. Turabian (also known as Chicago style) is a good choice, very well accepted in Social Sciences.

The critique point must be specific. Is it omitted variable bias? Then you must defend that 1 specific variable was omitted. Which is it? Is it measurement error? Then which variable has measurement error? Is it sample selection? Then are you concerned with selection in which specific way? You must provide evidence, and you can go as far as you want there. You can use pure logic, you can use newspaper sources. However, the royal evidence comes from actual research papers. If you want to really impress, you can bring outside datasets. There is no limit to the creativity you can put into the evidence for your point. Moreover, if you can solve the problem, then you should. It is not necessary to do this, and historically only 2 students per year manage to provide full solutions to the problems they suggest, but it certainly increases the level of impressiveness of your project to a whole new level.

The project has strict formatting rules. The paper cannot have more than 10 pages counting everything (except the cover page). It must be written in single-space, Times New Roman font size 12. The document must leave 1 inch of space in all margins, no more, no less. Pages must be numbered. Include a cover page with your name, student ID, and class time. Don’t try to fumble with the editing rules, because we have way too many examples to compare. You have a bit of freedom within reason in how you format and space the section titles, as well as figures and tables, if you have some. Here are some guidelines (not obligatory) to help you write the paper: a typical critique has a 2 page long introduction, then the critique itself is introduced in general lines in about half a page. The body of the critique is very free, and the conclusion is usually at most one page long.

The project is graded based on many things. First, the introduction where you summarize the paper. There we are looking for an excellent understanding of what truly matters in this year’s paper. The words about which you should think are conciseness, precision, and readability. To help you write this section, read question 2 in all midterms again. Many items there were designed to make you extract the essence of the paper arguments in a few lines.

The body of the paper is, of course, the most important part. We are looking for a good critique point, which is defended using excellent evidence. The critique must clearly delineate what are the consequences of the problem you are raising. We reward creativity very highly. You can defend the same critique point as many of your colleagues, but then you are in direct comparison with them. If you choose an unexplored critique point, you will be evaluated on your own, which is a good thing. Moreover, when we see a novel critique point, we imagine that you thought about, but rejected, several more common ideas. Hence, we will reward you directly. We also reward the quality of the evidence. Not all evidence has the same strength and reliability. It goes like this: straight from data>>research papers>>online verifiable journalistic sources>>logical argument. This is not written in stone, but it’s a decent guideline. We reward effort and creativity involved in choosing, searching, and using the evidence. We also reward the strength of your whole argument. Is it easy to understand? Are you convincing?

You can make up for things. For example, you may not be defending the most creative critique point, but you can make up for it with a brilliant evidence source, or even (wow!) a direct solution. Additionally, this is an essay, so your language counts a lot. We establish just a few points for style and grammar, but don’t underestimate the power of a well written piece. An argument that develops fluidly, a paper that is not boring, a paragraph that is so well structured that the mind just cruises through it, all of those end up reflecting in your final grade. We punish pretty severely when your arguments are not clear, when we have to re-read things many times to get the point.

This project is not about doing everything right. Your paper may defend a correct critique point, use good evidence, and be sufficiently clear, and it will still not garner the maximum grade. You can always choose to break free from mediocrity. You can choose to be ambitious, to risk, and we will reward that.

Final note: you can get help with grammar and style. Check out this link to the
College Writing Program. They can read your essay over, they can help edit it. You should take advantage of this resource, it will serve you well for when you are writing other essays in the future. Do you see how journalists write? This style is very persuasive. I’ve seen undergrad students that could write this smoothly, and we couldn’t help but give them a better grade. Never underestimate the importance of presentation, be it in person or in paper.

The project is due on 04/29/15 in class. It must be handed in paper (print and staple it).

Midterm 2 answers published

I just published the exam answers. You can find them in the downloads page.

Typo on the exam preparation

There was a typo on Question 1, item h. The beta_5 should be beta_1, of course. I corrected it. There was also a typo on the model in item a before. I had beta_2 twice there, but I fixed that one as well a few days ago.

Extra office hours

Your TA Zach will be holding his office hours on Tuesday from 6:15-9:30 in Meliora 210 on Tuesday. Starting at 7:30, he will also be having live help hours on the forum. He will not hold his normal office hours and LHE this Thursday.

Midterm 2 preparation

Midterm 2 preparation is published in the download page.

This document has all the questions that will be in the actual midterm, with 2 differences: (1) the Material Question will have an actual situation, with real variables like class attendance and smoking. The preparation has generic variables like y and x
1. (2) In the midterm you will only receive a subset of these questions, so that you have time to answer them. If you want to know more about the intentions behind the midterm and how to prepare, read this.

The midterm will take place in the regular classroom in the regular class time. You should plan around 1 to 1:05 hour to write your answers.

I will give you one booklet with the questions, and two other booklets, one for the Material Question, and one for the Paper Question. These booklets have space for answering each of the items. Since the answer space of each question is set, you don’t need to write the answers in a row. You can write the bulk of the answers to all questions, and if you have extra time you may go back and complete them with extra flourishes.

Extra ofice hour for the Replication!

Your TA Alon will be holding a special office hour Monday 6-7pm at Harkness 208. Bring him your questions about the replication!

Deadline of Replication Extended

I am extending the deadline of the replication to Tuesday March 31st at 5 pm. All the other rules are the same, just adapted for the new deadline date. This will give you 4 more days to complete the replication. Use the time wisely!

Extra office hour

Your TA Alon will be tomorrow Tuesday 03/24 from 5 to 6:30 pm at Hark 208. Bring your Replication questions. If you are having difficulty getting started, don’t miss this opportunity of getting help from him!

Stata 13

Harkness 114 now has Stata 13 in all computers. The other computers in the university still run Stata 11. Unfortunately they will only update them in the summer.

Problems opening the replication data set

Some students were not able to open the data set because it was not compatible with older versions of Stata. I uploaded a new data set version which should now be compatible. Please let us know in the forum if you are still having trouble.

Replication

You will replicate the project paper (the same one of question 2 in the Midterm). This means that you will get the data and clean it according to the descriptions in the paper. You can find the data, the codebook, a link to the interactive codebook online and a small document with some recommendations about the replication in the Project part of the Download page. Then you will generate the same variables that the authors say they do, and run the same regressions. Finally, you will make sure that your code presents all the values in the table in a format that is very easy to see. You need to reproduce Tables 1 and 2 (no need to reproduce Table 3).

The code must be clean and organized. You have a good measure of freedom in deciding how you will organize your code. The point is to use comments to create sections for each different part of the replication. You should also use comments to explain what the commands are doing. The way you should approach this is as someone who is writing a code that will be used by others. Could they run it if they had the same data set? Could they understand it with minimum effort?

As with the homeworks, this assignment is a .do file. One .do file. You are graded on the correctness of what you did, on how close you get to the results, on how clean and elegant is your code, and on how easy it is to understand. Think that you are working with a coauthor, or with colleagues in a company. You don’t want to explain so much that it is tiresome to read, but you must make sure that the reader doesn’t spend time figuring out what you intended with this or that command.

The replication is usually a challenging assignment. The hard truth is that you can very seldom replicate exactly the same results of a paper. Sometimes papers have mistakes, but even when they don’t, the authors may have done something with the data that they didn’t describe in the paper, perhaps by distraction, perhaps intentionally. So, you won’t get the same results that they did. How close can you get? As you try to figure this out you will gain a very deep understanding of the paper.

Usually this process is very time consuming. Don’t play with this, you never replicated a paper before, you don’t know what it is like. You will run into coding problems, you may need to learn a Stata trick, you may have to start again. Even when you get it to run, you may not be getting results that are close enough, what are you doing differently? You will need time to go to office hours and experiment until you figure it out.

Alon is the specialist in the replication. He will hold grading office hours for Homework 3, but you can come and ask him questions about the replication as well. David can definitely help you, though he will have to figure things out with you. The undergrad TAs have done replications of their own when they took this course, so they can help as well. However, on this particular assignment, try to get the grad TAs to help you if you can.

The replication is due on Friday 03/27 at 5:00 pm. You must upload the replication file in the upload page. For details on how to upload it, read this. The password is still the same as for the homeworks. The replication is graded out of 50 points, and it is worth 10% of the grade.
 

PENALTIES IF THE FILE DOESN’T RUN
If your .do file doesn’t run, the TA will request that you fix it, and give you a deadline (usually until the next day). Each time he has to request a correction for the file to run, you lose 10 points. If you fail to make the deadline of a correction request, your replication won’t be accepted anymore. You choose which email we will use to contact you when you upload the file. Make sure that it is one you check often.

LATENESS PENALTIES
Every hour past the due time, your replication loses 10 points. Here is a breakdown:

Received before 5:00 pm until 5:59: no penalty
Received between 6:00 and 6:59: -10
Received between 7:00 and 7:59: -20


and so on until 10 pm, at which time we will not accept your replication any longer. Read the policy on late assignments here.

NOTICE: the replication is due before or at 5:00 pm. We only start discounting points at 6:00 pm to allow for internet delays, browser reloading or any other unpleasant things that may happen. We will not accept any excuse related to technology. If you can’t rely on your connection, or your browser, then take measures to upload your homework earlier, or even better, the night before.

Think that there are way too many rules to follow in this course? Read this.

Extra help from a TA

Your TA Zach will be this evening either at Meliora 210 or at Hark114 helping students with homework 3. After midnight he will move to ITS if necessary and stay there until very late. Check the forum for details.

More videos posted

Find 4 new Stata videos posted in our channel. The links are in the downloads page.

Change in office hour time and location

Welcome back from Spring Break! Your Stata TA Zach will no longer hold his Friday afternoon office hour. Instead we are transferring his office hour to Thursdays 6:15-7:30 at Mel 210. Check the calendar for details. We hope that this will serve you better in the coming assignments.

Stata videos

As you know, I will be out of town this week. I don’t know how good my internet access will be, so I may not be able to post anything this week. In case I can’t post, you should know that your TA David will be posting new Stata videos this week. The videos will be in our YouTube channel (find the link in the Download page). He will announce when he has done so in the Forum, so be sure check it out at least once a day this week to find out when the videos are up.

No Friday 2-3:15 office hour

Your TA Zach will NOT be holding his usual Friday 2-3:15pm office hour this coming Friday 03/06. If you were planning to attend, please email him directly to arrange to see him some other time.

Homework 3 is posted

You can find homework 3 in the download page.

Homework 3 is due on Friday 3/20 (which is the week right after Spring Break) at 12:00 pm. You must upload the homework file in the
upload page the same way you did with homework 2. The password is the same as homework 2.

Your homework is a .do file (
ONE .do file!). You should know by now how to produce it. Find the data sets in the download page, unless specified in the homework.

PENALTIES IF THE FILE DOESN’T RUN

If your .do file doesn’t run, the TA will request that you fix it, and give you a deadline (usually until the next day). Each time he has to request a correction for the file to run, you lose 2 points (
THE PENALTY WENT UP FROM LAST HOMEWORK). If you fail to make the deadline of a correction request, your homework won’t be accepted anymore. You choose which email we will use to contact you when you upload the file. Make sure that it is one that you check often.

LATENESS PENALTIES

Every hour past the due time, your homework loses 2 points. Here is a breakdown:

Received before 12:00 until 12:59: no penalty
Received between 1:00 and 1:59: -2
Received between 2:00 and 2:59: -4


and so on until 5 pm, at which time we will not accept your homework any longer. Read the policy on late homeworks
here.

NOTICE: the homework is due before or at 12:00 pm. We only start discounting points at 1:00 pm to allow for internet delays, browser reloading or any other unpleasant things that may happen. We will not accept any excuse related to technology. If you can’t rely on your connection, or your browser, then take measures to upload your homework earlier, or even better, the night before.

Think that there are way too many rules to follow in this course? Read
this.

No class next week, also no professor office hour

This post is just a reminder that there will be no class next week (03/02 and 03/04), as I will be out of town. I won’t hold my regular office hour on Monday 03/02 either. This does not affect the course plan, because it was predicted before the beginning of the semester. The TAs will hold their regular activities as usual on the next week. Of course, all regular course activities, office hours, LHE, etc. stop for the Spring Break. Check the class calendar if you are in doubt. Make sure to get plenty of work done next week, enjoy Spring Break, and see you on the other side.

Extra Stata office hours

Your TA Zachary has graciously offered to hold extra office hours today (Thursday), 6:30-9:00pm at HARK 114. Bring your homework questions!

More Stata videos posted

You can find 4 new Stata videos in the Downloads page. You need to watch videos 2 to 8 for Homework 2.

About the .do files

Your homework is 1 .do file. Even if the homework has several questions, you must write 1 .do file that answers all. Make sure that you read the FAQ question about the .do files linked here. Also, to minimize the likelihood that your file does not run, always:

1. make sure to use the 'clear' command before using any data set in your do-files so that any previous data in STATA's memory can be cleared away.
2. with the 'use' command don't give in the entire path name of the data set, just write, use GPA2.dta, for example. You can set the home directory separately using 'cd'. The TA will then change the path and run the entire file without any problem.

Remember, you lose points if the file does not run on another person’s computer, so be careful with that. Ask any of the TAs if you have questions about that, especially the Stata TAs.

Password to upload the homework

You will need a password to upload the homework. I will be giving the password in the following classes:

02/23 and 02/25

Make sure that you come to at least one of these classes. Otherwise, ask another student that attended the class to tell you what it is.

Homework 2 is posted

You can find homework 2 in the download page.

Homework 2 is due on Friday 2/27 at 12:00 pm. You must upload the homework file in the
upload page. For details on how to upload your homework, read this. You will need a password. I will post another announcement with the instructions on how to get the password. Make sure that you read it.

Your homework is a .do file (
ONE .do file!). For details about what is, and how to produce a .do file for your homework, read this (but more importantly, watch the Stata videos). Find the data sets in the download page, unless specified in the homework.

PENALTIES IF THE FILE DOESN’T RUN

If your .do file doesn’t run, the TA will request that you fix it, and give you a deadline (usually until the next day). Each time he has to request a correction for the file to run, you lose 1 point (in the following homework you lose 2 points). If you fail to make the deadline of a correction request, your homework won’t be accepted anymore. You choose which email we will use to contact you when you upload the file. Make sure that it is one that you check often.

LATENESS PENALTIES

Every hour past the due time, your homework loses 2 points. Here is a breakdown:

Received before 12:00 until 12:59: no penalty
Received between 1:00 and 1:59: -2
Received between 2:00 and 2:59: -4


and so on until 5 pm, at which time we will not accept your homework any longer. Read the policy on late homeworks
here.

NOTICE: the homework is due before or at 12:00 pm. We only start discounting points at 1:00 pm to allow for internet delays, browser reloading or any other unpleasant things that may happen. We will not accept any excuse related to technology. If you can’t rely on your connection, or your browser, then take measures to upload your homework earlier, or even better, the night before.

Think that there are way too many rules to follow in this course? Read
this.

3 new videos published

You can find 3 new Stata videos in our channel. The links are in the downloads page. They are the first videos that teach you to deal with the program itself. It is a good idea to start watching soon and get on with homework 2 as soon as possible. You never know how much time programming will take.

Midterm 1 answers published

I just published the exam answers. You can find them in the downloads page.

About the paper part of the Midterm

I received a question by email which made me a bit concerned. Lest there be any confusion, let me be clear: the paper part of the midterm refers to the project paper, which can be found in the Downloads page. The paper will not be given to you during the exam, nor are you allowed to bring it with you. However, if the question refers to a table in the paper, I will include a copy of the table in the exam.

About the Adjusted R-squared

The paper uses a modified form of the R2, the “adjusted R2.” Here is a small explanation about what it means.

Remember that the R
2 never decreases when we add more explanatory variables, and in fact often increases, even if the variable should not be included at all. For example, consider the final grade problem we discussed in class. Say that we included the explanatory variables # classes attended, # office hours attended, and # sections attended. Now, if we add the variable “number of times the student said hello to the instructor,” we can all agree that it is a very silly thing to add to the model, right? Formally this variable is probably not a confounder. However, the R2 may actually increase anyway.

The adjusted R
2 penalizes the inclusion of new variables in such a way that it only increases if the new variable improves the fit more than what would be expected to improve anyway by chance.

Note that the interpretation of the adjusted R
2 differs from the interpretation of the R2. The R2 is a measure of how well the regression line fits the data. The adjusted R2 helps to compare the fit quality of two regressions. In the example above, we can use adjusted R2 to compare the regression that included hours spent studying to the regression that did not include this variable.
Thus, adjusted R
2 is useful in selecting which regression is best. It is worth mentioning that in a univariate regression the R2 will be equivalent to the adjusted R2. In a multivariable regression, these two measures of the model's performance will generally differ.

Extra Office Hour

Your Material TA Sol has graciously volunteered to give an extra office hour for the midterm. Tomorrow (Friday) at 3pm he will be at HARK 113 to help out with any questions you may have about the exam.

Midterm 1 preparation

Midterm 1 preparation is published in the download page.

This document has all the questions that will be in the actual midterm, with 2 differences: (1) the Material Question will have an actual situation, with real variables like class attendance and smoking. The preparation has generic variables like y and x
1. (2) In the midterm you will only receive a subset of these questions, so that you have time to answer them. If you want to know more about the intentions behind the midterm and how to prepare, read this.

The midterm will take place in the regular classroom in the regular class time. You should plan around 1 to 1:05 hour to write your answers.

I will give you one booklet with the questions, and two other booklets, one for the Material Question, and one for the Paper Question. These booklets have space for answering each of the items. Since the answer space of each question is set, you don’t need to write the answers in a row. You can write the bulk of the answers to all questions, and if you have extra time you may go back and complete them with extra flourishes.

Introducing this semester's paper!

The paper we will be using this semester is

Gender Differences in the Effect of Education on the Slope of Experience-Earnings Profiles

by Kevin C. Duncan. It was published in 1996 by the American Journal of Economics and Socioloy.

This is a classic topic in Economics. There exist a large literature on earning gaps due to gender (and also racial, height, beauty, etc.) differences. The issue is whether this is due to discrimination or actual productivity differences.

We will be using this paper in the midterm questions, in the replication, and in the project.

Typo in Homework 1

There was a typo in Question 1 (a). It should read: “Briefly describe the ELS:2002 survey and whether it can be useful for the question in which the researcher is interested.” Originally I had ELS:2000, but that was just a typo, it should say ELS:2002.

Video definition fixed

Well, there was not really any issue. YouTube just takes a while to fully process the videos and then offer them at the maximum definition. Usually, at most 24 hours after we publish our videos you should be able to watch them in full definition.

Homework 1 is posted

You can find homework 1 in the download page.

Homework 1 is due on Friday 02/06 at 12:00 pm. You must leave it in the ECO 231W box in Harkness (there are two boxes there, either is fine). The Stata homework TA will collect them at exactly that time, so make sure that your homework is there before this time.

Your homework must be legible and organized, or you may get penalized.

Read the policy on late homeworks
here.

ATTENTION: remember to write your name (as it appears in your transcript), student ID, and class time or we may not record your grade.

The first video is uploaded

I uploaded the first Stata tutorial video. Check out the Download page. Unfortunately the video is not uploading at the maximum resolution. We are working to make this happen soon. Meanwhile, if you know how to upload videos to YouTube in HD, please let us know!

Email form problem solved!

The email form in the Contact us page is working now. If you need to send me an email, make sure to use that form instead of my regular email. If your question is of a general nature, ask it in the Forum.

Email form problems

The email form in the Contact us page seems to be having some problems. Until I fix it, do not use it to send me emails. Instead, if you need to email me, use my regular email in this link. If you emailed me using the form, I did not receive your email. Please email me again. If your question is of a general nature, ask it in the Forum.

Prof. Caetano's Office Hours

In case you did not notice it in the Calendar page, my office hours are now on Mondays 2-3pm on HARK 213. I originally scheduled them on Wednesdays, but we had a conflict with one of the lab office hours.

You can always find all the office hours times and locations in the
Calendar.

Welcome to ECO 231W Spring 2015!

This page contains all the announcements for the course. It is your obligation to keep up with it. Here I post all the rules concerning assignments, and I also let you know if there will be any change. Did you read the Check-in page? That should be your first stop.