We were asked to discuss specific methodological approaches to evaluating three hypothetical interventions. This article uses this forum to discuss three misperceptions about randomized trials. First, nobody argues that randomized trials are appropriate in all settings, and for all questions....

Many social experiments are run in multiple waves, or are replications of earlier social experiments. In principle, the sampling design can be modified in later stages or replications to allow for more efficient estimation of causal effects. We consider the design of a two-stage experiment for...

Firms spend billions of dollars each year advertising consumer products in order to influence demand. Much of these outlays are on the creative design of advertising content. Creative content often uses nuances of presentation and framing that have large effects on consumer decision making in...

In much of the developing world, many farmers grow crops for local or personal consumption despite export options which appear to be more profitable. Thus many conjecture that one or several markets are missing. We report here on a randomized controlled trial conducted by DrumNet in Kenya that...

Group liability in microcredit purports to improve repayment rates through peer screening, monitoring, and enforcement. However, it may create excessive pressure, and discourage reliable clients from borrowing. Two randomized trials tested the overall effect, as well as specific mechanisms. The...

Microfinance has been heralded as an effective way to address imperfections in credit markets. But from a theoretical perspective, the success of microfinance contracts has puzzling elements. In particular, the group-based mechanisms often employed are vulnerable to free-riding and collusion,...

We develop and test a simple model of limited attention in intertemporal choice. The model posits that individuals fully attend to consumption in all periods but fail to attend to some future lumpy expenditure opportunities. This asymmetry generates some predictions that overlap with models of...

Information asymmetries are important in theory but difficult to identify in practice. We estimate the presence and importance of hidden information and hidden action problems in a consumer credit market using a new field experiment methodology. We randomized 58,000 direct mail offers to former...