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development impact links

Weekly links July 28: overpaid teachers? Should we use p=0.005? beyond mean impacts, facilitating investment in Ethiopia, and more…

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  • Well-known blog skeptic Jishnu Das continues to blog at Future Development, arguing that higher wages will not lead to better quality or more effective teachers in many developing countries – summarizing evidence from several countries that i) doubling teacher wages had no impact on performance; ii) temporary teachers paid less than permanent teachers do just as well; and iii) observed teacher characteristics explain little of the differences in teacher effectiveness.
  • Are we now all doomed from ever finding significance? In a paper in Nature Human Behavior, a multi-discipline list of 72 authors (including economists Colin Camerer, Ernst Fehr, Guido Imbens, David Laibson, John List and Jon Zinman) argue for redefining statistical significance for the discovery of new effects from 0.05 to using a cutoff of 0.005. They suggest results with p-values between 0.005 and 0.05 now be described as “suggestive”. They claim that for a wide range of statistical tests, this would require an increase in sample size of around 70%, but would of course reduce the incidence of false positives. Playing around with power calculations, it seems that studies that are powered at 80% for an alpha of 0.05 have about 50% power for an alpha of 0.005. It implies using a 2.81 t-stat cutoff instead of 1.96. Then of course if you want to further adjust for multiple hypothesis testing…

Weekly links July 21: a 1930s RCT revisited, brain development in poor infants, Indonesian status cards, and more…

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Weekly links July 7: Making Jakarta Traffic Worse, Patient Kids and Hungry Judges, Competing for Brides by Pushing up Home Prices, and More…

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  • In this week’s Science, Rema Hanna, Gabriel Kreindler, and Ben Olken look what happened when Jakarta abruptly ended HOV rules – showing how traffic got worse for everyone. Nice example of using Google traffic data – MIT news has a summary and discussion of how the research took place : “The key thing we did is to start collecting traffic data immediately,” Hanna explains. “Within 48 hours of the policy announcement, we were regularly having our computers check Google Maps every 10 minutes to check current traffic speeds on several roads in Jakarta. ... By starting so quickly we were able to capture real-time traffic conditions while the HOV policy was still in effect. We then compared the changes in traffic before and after the policy change.”All told, the impact of changing the HOV policy was highly significant. After the HOV policy was abandoned, the average speed of Jakarta’s rush hour traffic declined from about 17 to 12 miles per hour in the mornings, and from about 13 to 7 miles per hour in the evenings”
  • From NPR’s Goats and Soda: 4-year kids of Cameroonian subsistence farmers take the marshmallow test, as do German kids – who do you think did best?

Weekly links June 30: 7th grade development economics, the beginning at the end approach, stuff that happened a long time ago still impacts today, and more…

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  • How to teach development economics in 20 minutes to 7th graders – Dave Evans explains his method.
  • The “beginning at the end” approach to experimentation – written from the point of view of business start-ups, but could easily apply to policy experiment work too “The typical approach to research is to start with a problem. In business, this often leads to identifying a lot of vague unknowns—a “broad area of ignorance” as Andreasen calls it—and leaves a loosely defined goal of simply reducing ignorance…“Beginning at the end” means that you determine what decision you’ll make when you know the results of your research, first, and let that dictate what data you need to collect and what your results need to look like in order to make that decision.”

Weekly links June 23: VoxDev launches, uncountable Nigerians, a challenge to prospect theory, and more…

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Weekly links June 16: why women earn less, teaching fintech, now class size doesn’t matter, and more…

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  • Women in Economics at Berkeley has a great summer reading list of recent papers which look at the gender earnings gap in different ways, including short summaries of some very recently published papers in the AER, QJE, and JPE on this issue.
  • The NYTimes on how business schools are trying to teach fintech, although with no agreement on what this means or how to do it.

Weekly links June 9: the dangers of out-dangering, debating how to provide health care for the poor, fighting corruption, and more…

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  • Milli Lake and Sarah Parkinson on the ethics of fieldwork preparedness – “It’s one of the discipline’s worst kept secrets that graduate students, in particular, feel practically unprepared for their fieldwork… We worry about an intellectual trend that increasingly rewards researchers for “out-dangering” one another (often with dubious scholarly gain). This doesn’t mean scholars should abandon fieldwork; it means that we should take the practical and ethical components of its planning and implementation more seriously. We can start by asking simple questions about first aid, check-ins, transport safety, and data protection”

Weekly links June 2: do you need to correct your p-values for all the tests you run in your life?, nimble RCTs, the elusive entrepreneur, and more…

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Weekly links May 26: the Chetty production function, collect priors before you work, small samples bring trouble, and more…

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