A standard methodology in program evaluation is to use time series variation to compare pre- and post-program outcomes. However, when the timing of a break in a statistical relationship can be determined only by looking at the data, then the usual distribution of the test statistic which assumes...

We investigate the problem of predicting the average effect of a new training program using experiences with previous implementations. There are two principal complications in doing so. First, the population in which the new program will be implemented may differ from the population in which the...

I argue for thinking of program evaluation as a decision problem. In the context of California's GAIN experiment (a randomized trial of a welfare-to-work alternative to AFDC), I show that GAIN first-order stochastically dominates AFDC when considering the choice between the treatment and control...

Improving "last-mile" public-service delivery is a recurring challenge in developing countries. Could the widespread adoption of mobile phones provide a scalable, cost-effective means for improvement? We use a large-scale experiment to evaluate the impact of phone-based monitoring on a program...

I explore the equilibrium value implications of economic models that incorporate reactions to a stochastic environment. I propose a dynamic value decomposition (DVD) designed to distinguish components of an underlying economic model that influence values over long horizons from components that...

This paper is a practical guide (a toolkit) for researchers, students and practitioners wishing to introduce randomization as part of a research design in the field. It first covers the rationale for the use of randomization, as a solution to selection bias and a partial solution to publication...

This paper contributes to the understanding of how to maximize the impact of publicly provided climate finance to leverage the private sector. Agencies seeking to promote private investment in support of climate change mitigation and adaptation may have a choice between subsidizing projects or...

How can we allow patent examiners to effectively distinguish between patentable and unpatentable inventions, without slowing the process to a crawl or wasting a bunch of money? This essay reviews the recent literature and considers a number of proposals and their limitations. It concludes that...

There is limited causal evidence on the effects of different public procurement regulations on project quality and value-for-money for projects funded by national governments and foreign aid donors. This paper uses policy and experimental variation to study how two key contracting...

The "voltage effect" is defined as the tendency for a program's efficacy to change when it is scaled up, which in most cases results in the absolute size of a program's treatment effects to diminish when the program is scaled. Understanding the scaling problem and taking steps to diminish...