Randomized experiments commonly compare subjects receiving a treatment to subjects receiving a placebo. An alternative design, frequently used in field experimentation, compares subjects assigned to an untreated baseline group to subjects assigned to a treatment group, adjusting statistically...

In recent years, social scientists have increasingly turned to matching as a method for drawing causal inferences from observational data. Matching compares those who receive a treatment to those with similar background attributes who do not receive a treatment. Researchers who use matching...

Previous research shows that partisans rate the economy more favorably when their party holds power. There are several explanations for this association, including use of different evaluative criteria, selective perception, selective exposure to information, correlations between economic...

A secret ballot is implemented to free voters to choose candidates without fear of economic or social repercussions, but the extent to which the secrecy achieves this goal depends on whether people believe their choices are kept secret, rather than whether they actually are. Findings from a...

Prior to the November 6, 2001 elections, randomized voter mobilization experiments were conducted in Bridgeport, Columbus, Detroit, Minneapolis, Raleigh, and St. Paul. Names appearing on official lists of registered voters were randomly assigned to treatment and control groups. A few days before...

If the publication decisions of journals are a function of the statistical significance of research findings, the published literature may suffer from "publication bias." This paper describes a method for detecting publication bias. We point out that to achieve statistical significance, the...

Political campaigns currently make extensive use of direct mail, particularly in state and local races, yet its effects on voter behavior are not well understood. This essay presents the results of large-scale randomized field experiments conducted in Connecticut and New Jersey during state and...

The debate about the cost-effectiveness of randomized field experiments ignores one of the most important uses of experimental data. This article defines and illustrates "downstream" experimental analysis - that is, analysis of the indirect effects of experimental interventions. We argue that...

We report the results of a randomized field experiment involving approximately 30,000 registered voters in New Haven, Connecticut. Nonpartisan get-out-the-vote messages were conveyed through personal canvassing, direct mail, and telephone calls shortly before the November 1998 election. A...

Missing outcome data plague many randomized experiments. Common solutions rely on ignorability assumptions that may not be credible in all applications. We propose a method for confronting missing outcome data that makes fairly weak assumptions but can still yield informative bounds on the...