Online discussion forums have been shown to contribute to the trust and cohesion of groups, and their use has been associated with greater overall engagement in online courses. We devised two experimental interventions to encourage learners to participate in forums. A collectivist (“your participation benefits everyone”), individualist (“you benefit from participating”), or neutral (“there is a...

Banning a¢rmative action from college admissions decisions cannot prevent an admissions o¢ce that cares about diversity from achieving it through channels other than the explicit consideration of race. We construct a model of college admissions where candidates from two groups with di¤erent average quali...cations compete for a ...xed number of seats. When an admissions o¢ce that cares both abo...

Whereas the effects of maternal parenting quality during infants' 2nd year on later executive function (EF) have been studied extensively, less is known about the impact of maternal parenting quality during the 1st year. The aim of this study was to examine whether maternal parenting during infants' 1st year predicted EF performance at 2 and 3 years of age in a Chinese sample. Data were collect...

Peer effects, in which the behavior of an individual is affected by the behavior of their peers, are central to social science. Because peer effects are often confounded with homophily and common external causes, recent work has used randomized experiments to estimate effects of specific peer behaviors. These experiments have often relied on the experimenter being able to randomly modulate mech...

1. Curso de Pós-Graduação em Ciências Biológicas, Núcleo de Pesquisa em Ciências Biológicas, Laboratório de Doença de Chagas, Universidade Federal de Ouro Preto. Ouro Preto, MG. Endereço para correspondência: Guilherme Malafaia. Rua Vereador Paulo Elias 8A, Vila Itacolomy, 35400-000 Ouro Preto, MG. Tel: 55 31 8696-5353 e-mail: [email protected] Recebido para publicação em 17/08/2009 Aceit...

In this paper, we considered a missing outcome problem in causal inferences for a randomized encouragement design study. We proposed both moment and maximum likelihood estimators for the marginal distributions of potential outcomes and the local complier average causal effect (CACE) parameter. We illustrated our methods in a randomized encouragement design study on the effectiveness of flu shots.