Market economies and pro-social behavior: Experimental evidence from Central Asia

This study seeks to extend the body of knowledge of pro-social behavior in comparative market settings by reporting on a high-stakes ultimatum game and revelation game experiments in two transition economies: Kazakhstan and Uzbekistan. While controlling for cultural differences and framing effects, we find statistically significant differences in fairness and honesty behavior between the two countries. Specifically, subjects in Uzbekistan (in an earlier stage of transition to a market economy) are fairer and more honest than their later-stage Kazakh counterparts. Our experimental findings have implications for the literature on pro-social behavior and market economies, and more generally, on the transmission process between formal and informal institutions.     

Amplification of Sensitivity Analysis in Matched Observational Studies

A sensitivity analysis displays the increase in uncertainty that attends an inference when a key assumption is relaxed. In matched observational studies of treatment effects, a key assumption in some analyses is that subjects matched for observed covariates are comparable, and this assumption is relaxed by positing a relevant covariate that was not observed and not controlled by matching. What properties would such an unobserved covariate need to have to materially alter the inference about treatment effects? For ease of calculation and reporting, it is convenient that the sensitivity analysis be of low dimension, perhaps indexed by a scalar sensitivity parameter, but for interpretation in specific contexts, a higher dimensional analysis may be of greater relevance. An amplification of a sensitivity analysis is defined as a map from each point in a low dimensional sensitivity analysis to a set of points, perhaps a 'curve,' in a higher dimensional sensitivity analysis such that the possible inferences are the same for all points in the set. Possessing an amplification, an investigator may calculate and report the low dimensional analysis, yet have available the interpretations of the higher dimensional analysis.     

Using quantile averages in matched observational studies

In two observational studies, one investigating the effects of minimum wage laws on employment and the other of the effects of exposures to lead, an estimated treatment effect's sensitivity to hidden bias is examined. The estimate uses the combined quantile averages that were introduced in 1981 by B. M. Brown as simple, efficient, robust estimates of location admitting both exact and approximate confidence intervals and significance tests. Closely related to Gastwirth's estimate and Tukey's trimean, the combined quantile average has asymptotic efficiency for normal data that is comparable with that of a 15% trimmed mean, and higher efficiency than the trimean, but it has resistance to extreme observations or breakdown comparable with that of the trimean and better than the 15% trimmed mean. Combined quantile averages provide consistent estimates of an additive treatment effect in a matched randomized experiment. Sensitivity analyses are discussed for combined quantile averages when used in a matched observational study in which treatments are not randomly assigned. In a sensitivity analysis in an observational study, subjects are assumed to differ with respect to an unobserved covariate that was not adequately controlled by the matching, so that treatments are assigned within pairs with probabilities that are unequal and unknown. The sensitivity analysis proposed here uses significance levels, point estimates and confidence intervals based on combined quantile averages and examines how these inferences change under a range of assumptions about biases due to an unobserved covariate. The procedures are applied in the studies of minimum wage laws and exposures to lead. The first example is also used to illustrate sensitivity analysis with an instrumental variable.     

HOME-BASED MARITAL THERAPY FOR MULTIPROBLEM FAMILIES*

This paper describes a project designed to reach low-income, multiproblem families, utilizing couples therapy in the home. By targeting a population of young couples under the age of 30 and with children no older than 7 years, the project aimed at prevention of severe family dysfunctioning and child disturbances. The major characteristics noted in the literature on multiproblem families are reviewed here, as are the treatment goals and techniques with such families. Most programs working with multiproblem families have focused primarily on the parental functioning in family therapy, and little has been reported on work with the couple in multiproblem families. The project described here used home visits by a male-female therapist team, including frequent individual and couple sessions. Therapeutic techniques based on modeling, role playing and demonstration were emphasized. In addition, tasks which increased the individual and couple functioning of the spouses were designed and successful completion was reinforced. An attempt was made to integrate the couple into the community and to create a network of support outside of the family, including friends and community services.     

Worksite e-mail health promotion trial: Early lessons

In preparation for an electronic mail (e-mail) and web-based health promotion intervention across multiple worksites, secure, regulatory-compliant, user-friendly e-mail and Internet applications were used to recruit potential participants across worksites, to enroll participants, and to collect baseline health assessment data. Specific hardware and software information technology environments were required of the 19 participating worksites. Sequential e-mails introduced the study and invited participation. Twenty-four percent of all employees (1106 of approximately 4600) provided consent. E-mail delivered a web link for the baseline study assessment, and reminder e-mails were sent to prompt completion. Of those who consented, 888 (80%) completed baseline health and behavior data surveys. An HTML-native web survey software was more stable across computing environments. Using e-mail and web assessment, this research recruited, enrolled, and collected data from more than 850 participants. Technical and operational challenges emerged at each step. Solutions and recommendations are discussed. Overall, this experience suggests that the use of e-mail and web software can facilitate recruitment, enrollment, and data acquisition through direct contact with study participants. This experience yields a series of lessons learned for using e-mail and the Internet to support multi-site trials.     

Sensitivity analysis for two control groups

In many experiments where data have been collected at two points in time (pre-treatment and post-treatment), investigators wish to determine if there is a difference between two treatment groups. In recent years it has been proposed that an appropriate statistical analysis to determine if treatment differences exist is to use the post-treatment values as the primary comparison variables and the pre-treatment values as covariates. When there are several outcome variables, we propose new tests based on residuals as alternatives to existing methods and investigate how the powers of the new and existing tests are affected by various choices of covariates. The limiting distribution of the test statistic of the new test based on residuals is given. Monte Carlo simulations are employed in the power comparisons.     

The context of infants' giving gestures in mother-infant dyads: Typical giving gestures and those contingent on exploration and play

This study aimed to focus on a niche that has not yet been investigated in infants' gesture studies that is the effect of the prior context of one specific gestural behavior (gives) on maternal behavior. For this purpose, we recruited 23 infants at 11 and 13 months of age yielded 246 giving gesture bouts that were performed in three contexts: typical when the object was offered immediately, contingent on exploration, and contingent on play. The analysis revealed that maternal responses to infants' giving gestures varied and were affected by their age and gesture context. Hence, mothers amended their responses according to the background that generated each gesture. The number of verbal responses to infants' giving gestures decreased as the infants aged, whereas the number of pretense responses increased. For infants aged 11 months, mothers generally provided motor responses to typical gestures. However, for infants aged 13 months, this trend declined and was replaced by a strong positive correlation between giving gestures contingent on play and verbal responses. We concluded that the type of activity with objects prior to employing giving gestures could enhance infants' symbolic skills because caregivers monitor the contingent act that yields the gesture that shapes their response.