Talk:Difference in differences

More Theory - Fewer Examples

I made an attempt at a formal definition of DID. We should also add a section on estimation of errors. Furthermore, we should relate this article to other Wikipedia articles in econometrics (perhaps regression analysis?). One good example to illustrate the implementation of DID should be sufficient, and I think we should keep Card & Krueger's paper on unemployment because it is very famous and easy to relate to. Using more than one example is probably more confusing than helpful. If nobody protests, I would like to clarify and make the Card and Krueger example more neutral, and then remove the other example. --Masalih (talk) 17:20, 29 December 2012 (UTC)

Although it kinda hurts to remove someone's efforts, I have now removed the "Hypothetical Example" section. I incorporated some of the lessons there in the new implementation section. I also put the reference to the hypothetical example as an external link at the bottom. --Masalih (talk) 20:27, 29 December 2012 (UTC)

I added an assumptions section and removed the second paragraph in the introduction, which I think repeated the message of the first paragraph and stated the assumptions of the model. --Masalih (talk) 08:54, 30 December 2012 (UTC)

Loose Thoughts?

The "Critics"-Section is a word by word copy of Betrand et al.... — Preceding unsigned comment added by 134.34.49.215 (talk) 11:44, 13 December 2011 (UTC)

let's get some explanation here: what is it!?!?

"Difference in differences" or "differences in differences"? Angrist and Pischke say the latter, as does the cited Bertrand et al. QJE article. — Preceding unsigned comment added by Spamdingel (talk • contribs) 18:03, 8 July 2011 (UTC) The blog post cited in the first footnote says "difference in difference". Who actually uses the phrase ("difference in differences") that is this entry's title? Spamdingel (talk) 18:06, 8 July 2011 (UTC)

I think there is no consensus on this, so I've added representative citations for each term in the first sentence.--Thosjleep (talk) 00:42, 13 December 2012 (UTC)

Removal or Change to Card and Krueger Example

I have issues with the way the Card and Krueger paper is used as an example. The way it is discussed focusses more on the results of the paper rather than using it as a pedagogical tool to discuss how diff-in-diffs work in practice. I also think it's a pretty bad paper, as evidenced by several criticisms (some discussion is here http://en.wikipedia.org/wiki/Minimum_wage#Card_and_Krueger). Therefore, it may not be the best paper to use as an example. It could be used as an example along with several other papers though. I think this would be better. It would highlight various types of diff-in-diffs papers from various disciplines. What does everyone else think? -PatrickButton (talk) 08:43, 5 April 2012 (UTC)

• I was under the impression that Card & Krueger were the first economists to employ this method, so their paper would be relevant at least as the first example, even if the methodology isn't perfect. I agree that it should be a discussion of the economic procedure, and not of their results, so the in/validity of their results wouldn't be a factor in this article. --Docmcconl (talk) 11:23, 17 October 2012 (UTC)
• I hope my rewritten version has solved this problem. --Masalih (talk) 20:36, 29 December 2012 (UTC)

Removing cleanup template

I'm removing the cleanup template, as it's unclear what is supposed to be cleaned up and I am not sure if there are fundamental problems with the article. Obviously, more can be done, but it doesn't seem to be an egregiously bad article.--Thosjleep (talk) 00:42, 13 December 2012 (UTC)