In recent conversations on research, I’ve noticed that we often get confused when discussing the placebo effect. The mere fact of positive change in a control group administered a placebo does not imply a placebo effect – the change could be due to simple regression to the mean.
So I have blogged in the past about the potential and the use of gender disaggregated data, but my work this past week in Ghana made me realize (again and in new ways) how complicated it can get in practice.
· Early results from a skills training program for young women in Liberia show massive increases in employment and earnings – although a randomized pipeline design whereby the control group get the treatment about one year after the treatment group raise concerns about strategic delay by the control group and how long-term impacts could be measured.
Many people are aware of the concept of a “placebo effect” in medicine and of the idea of a Hawthorne effect – in both cases the concern is that merely being treated can cause the treatment group in an intervention to change their behavior, regardless of what the treatment actually is.
· Marc Bellemare discusses a new paper in Science which finds young people, middle-aged people, and older people all believed they had changed a lot in the past but would change relatively little in the future – leading people to overpay for
Co-authored with Richard Akresh and Harounan Kazianga
Empirical evidence on the effectiveness of productivity incentives in the public sector is sparse. However donor enthusiasm is growing for this general approach and certain lessons are emerging.