· Chris Blattman on a new paper by David Card, Stefano DellaVigna, and Ulrike Malmendier on how many experiments are getting published in top economics journals, and on the role of theory in these.
David McKenzie's blog
Abhijit and Esther very graciously agreed to reply to Monday’s review of their book. Here is their reply, followed by a couple of additional thoughts from me.
Hot on the heels of More than good Intentions comes an outstanding new book by two of the most prominent leaders of the recent push for more rigorous evaluation – Abhijit Banerjee and Esther Duflo’s Poor Economics: A Radical Rethinking of the way to Fight Global Poverty
Millions of dollars are spent each year trying to improve the productivity of firms in Africa (and those in other developing countries), yet we have very little rigorous evidence as to what works. In a new working paper I look at whether it is even possible to learn whether such policies even work, and what can be done to make progress.
Small number of firms + Large heterogeneity = Not much power
In response to an earlier blog post on marketing experiments, we noted that young creative researchers are working with NGOs to try out new innovative ways to alleviate poverty and spur development. A reader wrote with the following question:
More than Good Intentions: How a new economics is helping to solve global poverty is a personalized helicopter tour of many recent randomized controlled trials (RCTs) in developing countries. It is written by Dean Karlan, who has been a researcher in many of these experiments, and Jacob Appel, who worked for Dean in implementing many of these experiments in Ghana.
There are now a variety of well-known experimental and non-experimental methods that economists use to learn whether a given program works or not. However, our tools for learning why or why not something works are much more limited.
The March 2011 issue of the Harvard Business Review has “a step-by-step guide to smart business experiments” by Eric Anderson and Duncan Simester, two marketing professors who have done a number of experiments with large firms in the U.S. Their bottom line message for businesses is:
Welcome to our new blog about impact evaluation. The number of impact evaluations both within and outside the World Bank have increased dramatically in recent years (see Figure below). The World Bank’s DIME initiative reports the number of active impact evaluations at the World Bank has increased from a couple of dozen in 2004 to over 250 in 2010. As a result, there are more producers and more consumers of impact evaluations than ever before – and more questions about how to conduct evaluations, what we are learning from these evaluations, and what can be done to learn more from them.
This blog has been set up by members of the Development Research Group at the World Bank to provide a forum for discussing these issues.
(Source: DIME. Figure shows impact evaluations by World Bank region: SAR = South Asia, MNA = Middle East and North Africa, LAC= Latin America and the Caribbean, ECA = Europe and Central Asia, EAP = East Asia and the Pacific, AFR = Sub-Saharan Africa)
Our goal is to cover a broad range of issues relating to impact evaluations, including:
- Summaries, critiques, and discussions of new research papers
- Discussions of ongoing and planned evaluations
- Methodological issues in doing experimental and non-experimental evaluations
Stories and puzzles from fieldwork
We want this blog to be something that is useful to both producers and consumers of impact evaluations, which can provide an opportunity for serious discussion and sharing of experiences. We hope to have a range of guest bloggers from both inside and outside the World Bank. We encourage all readers to not only participate in the discussions by commenting on blog posts, but also sending ideas and materials for blogs, as well as for guest blogging.
Please let us know in the comments any ideas you have for pressing issues to discuss, or topics you would like to see covered in future posts.