- 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…
- An overview/toolkit for distributional impact analysis in a new working paper by Bedoya et al. – and accompanying github page with Stata do files.
- At VoxDev, John Sutton on how Ethiopia is trying to reform its government investment agency. Also on VoxDev, Rajshri Jayaraman and Debraj Ray on how Indian tea pluckers exerted more effort in the short-run when given less performance-related pay; and Kaivan Munshi on how the caste system in India may foster group mobility, but hinder individual mobility.
- At Let’s Talk Development, Sabarwal and Abu-Jawdeh review the evidence on when parents compensate for versus reinforce differences among siblings in health and education.
- The control variables (or covariates) we include in a regression can affect the significance of the variable of interest; in impact evaluations, that’s the treatment variable. Marc Bellemare reviews a political science paper revealing how common covariate manipulation is, as well as a couple of methods to test the stability of your significance. (h/t Dave Evans).
- Call for papers: The Journal of Development Effectiveness is looking for interesting submissions on a variety of topics which address the issue of the effectiveness of policies, programs and projects in lower and middle-income countries and which use a variety of rigorous quantitative and qualitative techniques.
- Reminder: since we will take a blog break in August, a reminder that August 18 is the deadline for NEUDC submissions this year.
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