Many empirical questions in economics and other social sciences depend on causal effects
of programs or policies. In the last two decades, much research has been done on the …

The three main soil-transmitted helminth infections, ascariasis, trichuriasis, and hookworm,
are common clinical disorders in man. The gastrointestinal tract of a child living in poverty in …

Abstract Randomized Controlled Trials (RCTs) are increasingly popular in the social
sciences, not only in medicine. We argue that the lay public, and sometimes researchers, put …

That prenatal events can have life-long consequences is now well established.
Nevertheless, research on the fetal origins hypothesis is flourishing and has expanded to …

Media outlets often present diverging, even conflicting, perspectives on reality—not only
informing, but potentially misinforming audiences. We study the extent to which …

Problems involving causal inference have dogged at the heels of statistics since its earliest
days. Correlation does not imply causation, and yet causal conclusions drawn from a …

Conditional Cash Transfer (CCT) programs aim to reduce poverty by making welfare
programs conditional upon the receivers' actions. That is, the government only transfers the …

In this chapter, we present econometric and statistical methods for analyzing randomized
experiments. For basic experiments, we stress randomization-based inference as opposed …

This article examines the historical impact of railroads on the US economy, with a focus on
quantifying the aggregate impact on the agricultural sector in 1890. Expansion of the …

This survey gives a brief overview of the literature on the difference-in-difference (DiD)
estimation strategy and discusses major issues using a treatment effects perspective. In this …