Syndicate content

Blogs

What do 600 papers on 20 types of interventions tell us about how much impact evaluations generalize? Guest post by Eva Vivalt

This is the first in our series of posts by students on the job market this year.

Impact evaluations are often used to justify policy, yet there is reason to suspect that the results of a particular intervention will vary across different contexts. The extent to which results vary has been a very contentious question (e.g. Deaton 2010; Bold et al. 2013; Pritchett and Sandefur 2014), and in my job market paper I address it using a large, unique data set of impact evaluation results.
 
I gathered these data through AidGrade, a non-profit research organization I founded in 2012 that collects data from academic studies in the process of conducting meta-analyses. Data from meta-analyses are the ideal data with which to answer the generalizability question, as they are designed to synthesize the literature on a topic, involving a lengthy search and screening process. The data set currently comprises 20 types of interventions, such as conditional cash transfers (CCTs) and deworming programs, gathered in the same way, double-coded and reconciled by a third coder. There are presently about 600 papers in the database, including both randomized controlled trials and studies using quasi-experimental methods, as well as both published and working papers. Last year, I wrote a blog post for Development Impact based on this data, discussing what isn't reported in impact evaluations.

Blog links November 7: Impact Evaluation Existential Angst, Our Innate Grasp of Probability, big data, and More…

David McKenzie's picture

A Call for Innovative Ideas on SME Growth

David McKenzie's picture

I wanted to alert our readers to a new competition for ideas of how to best foster Small and Medium Enterprise (SME) growth.  Typically with impact evaluation we end up evaluating a program that others have designed, or working with the occasional bank or NGO that is willing to try a new idea, but usually with firms that are very small in size.  What is missing is a space where people with innovative ideas can get them into the hands of governments designing SME programs. I am working with the new Trade and Competitiveness Global Practice at the World Bank to try to do something new here, to give researchers and operational staff with ideas the chance to get them to a stage where they can become part of World Bank projects, and thereby have the potential to be implemented at much larger scale on lots of SMEs.

Business training that goes better with friends

Markus Goldstein's picture
The evidence on the effectiveness of business training is, at best, mixed (for an example, see my previous post on David McKenzie and Chris Woodruff's artful review).   As David and Chris point out, part of the problem was methods (esp. sample size).   But even when the methods were good, the results were often lackluster, particularly for women.  
 

A proposed taxonomy of behavioral responses to evaluation

Jed Friedman's picture

My summary of recent attempts to quantify the Hawthorne effect a few weeks back led to some useful exchanges with colleagues and commenters who pointed me to further work I hadn’t yet read. It turns out that, historically, there has been a great deal of inconsistent use of the term “Hawthorne effect”. The term has referred not only to (a) behavioral responses to a subject’s knowledge of being observed – the definition we tend to use in impact evaluation – but also to refer to (b) behavioral responses to simple participation in a study, or even (c) a subject’s wish to alter behavior in order to please the experimenter. Of course all these definitions are loosely related, but it is important to be conceptually clear in our use of the term since there are several distinct inferential challenges to impact evaluation arising from the messy nature of behavioral responses to research. The Hawthorne effect is only one of these possible challenges. Let me layout a classification of different behavioral responses that, if and when they occur, may threaten the validity of any evaluation (with a strong emphasis on may).

Blog links October 31: Frightful ethics? Ghastly preferences, Spooky Stata help, and more…

David McKenzie's picture
  • From the Stata blog: how to put the Stata user manuals on your ipad.
  • Chris Blattman discusses the controversy surrounding a field experiment being done by political scientists in the Montana election – much of the controversy seems very odd to a development economist –especially a concern that political scientists might actually be doing research that could affect politics….Dan Drezner notes the irony “political scientists appear to be damned if they do and damned if they don’t conduct experiments. In the absence of experimental methods, the standard criticism of political science is that it’s not really a science because of [INSERT YOUR PREJUDICE OF CHOICE AGAINST THE SOCIAL SCIENCES HERE]. The presence of experimental methods, however, threatens to send critics into a new and altogether more manic forms of “POLITICAL SCIENTISTS ARE PLAYING GOD!!” panic.”

A Technology Letdown: Efforts at using RFID technology to track microenterprise inventories

David McKenzie's picture
Measuring microenterprise profits is hard. Most owners of these small firms keep no records and have very volatile incomes.  Asking firm owners what their profits are can lead to high refusal rates, noisy data, trouble with recall, and then there is the added concern that reporting may change with interventions  (either because an intervention like business training changes recording, or because people who get given finance may want you to think it has benefited them).

Guest Post by Sebastian Galiani: Replication in Social Sciences: Generalization of Cause-and-Effect Constructs

I agree with the general point raised by Berk in his previous post in this blog (read it here). We need to discuss when and how to conduct scientific replication of existing research in social sciences. I also agree with him that, at least in economics, pure replication analysis –which in my view it is the only genuine replication analysis- is of secondary interest –I hope to return to this issue in a future contribution in this blog. Instead, I believe that we should emphasize replication of relevant and internally valid studies both in similar and different environments. There is now excessive confidence in the knowledge gathered by a single study in a particular environment, perhaps as a result of a misconstruction of the virtues of experimentation in social sciences. As Donald T. Campbell once wrote (1969):

It’s Time Again for Submissions for our Annual Blog Your Job Market Paper Series

David McKenzie's picture

We are pleased to launch for the fourth year a call for PhD students on the job market to blog their job market paper on the Development Impact blog.  We welcome blog posts on anything related to empirical development work, impact evaluation, or measurement. For examples, you can see posts from 2013 and 2012. We will follow the same process as previous years, which is as follows:
We will start accepting submissions immediately, with the goal of publishing them in November and early December when people are deciding who to interview. Below are the rules that you must follow, followed by some guidance/tips you should follow:
 

Pages