The internal relocation premium: are migrants positively or negatively selected? Evidence from Italy

This paper analyzes the wage returns from internal migration for recent graduates in Italy. We employ a switching regression model that accounts for the endogeneity of the individual's choice to relocate to get a job after graduation: the omission of this selection decision can lead to biased estimates, as there is potential correlation between earnings and unobserved traits, exerting an influence on the decision to migrate. The empirical results sustain the appropriateness of the estimation technique and show that there is a significant pay gap between migrants and non-migrants; migrants seem to be positively selected and the migration premium is downward biased through OLS estimates. The endogeneity of migration shows up both as a negative intercept effect and as a positive slope effect, the second being larger than the first: bad knowledge of the local labor market and financial constraints lead migrants to accept a low basic wage but, due to relevant returns to their characteristics, they finally obtain a higher wage than the others.     

Type I error rates from likelihood‐based repeated measures analyses of incomplete longitudinal data

The last observation carried forward (LOCF) approach is commonly utilized to handle missing values in the primary analysis of clinical trials. However, recent evidence suggests that likelihood‐based analyses developed under the missing at random (MAR) framework are sensible alternatives. The objective of this study was to assess the Type I error rates from a likelihood‐based MAR approach – mixed‐model repeated measures (MMRM) – compared with LOCF when estimating treatment contrasts for mean change from baseline to endpoint (Δ). Data emulating neuropsychiatric clinical trials were simulated in a 4 × 4 factorial arrangement of scenarios, using four patterns of mean changes over time and four strategies for deleting data to generate subject dropout via an MAR mechanism. In data with no dropout, estimates of Δ and SE_Δ from MMRM and LOCF were identical. In data with dropout, the Type I error rates (averaged across all scenarios) for MMRM and LOCF were 5.49% and 16.76%, respectively. In 11 of the 16 scenarios, the Type I error rate from MMRM was at least 1.00% closer to the expected rate of 5.00% than the corresponding rate from LOCF. In no scenario did LOCF yield a Type I error rate that was at least 1.00% closer to the expected rate than the corresponding rate from MMRM. The average estimate of SE_Δ from MMRM was greater in data with dropout than in complete data, whereas the average estimate of SE_Δ from LOCF was smaller in data with dropout than in complete data, suggesting that standard errors from MMRM better reflected the uncertainty in the data. The results from this investigation support those from previous studies, which found that MMRM provided reasonable control of Type I error even in the presence of MNAR missingness. No universally best approach to analysis of longitudinal data exists. However, likelihood‐based MAR approaches have been shown to perform well in a variety of situations and are a sensible alternative to the LOCF approach. MNAR methods can be used within a sensitivity analysis framework to test the potential presence and impact of MNAR data, thereby assessing robustness of results from an MAR method. Copyright © 2004 John Wiley & Sons, Ltd.     

Comparing aggregate and disaggregate forecasts of first order moving average models

This paper compares the performance of “aggregate” and “disaggregate” predictors in forecasting contemporaneously aggregated vector MA(1) processes. The necessary and sufficient condition for the equality of mean squared errors associated with the two competing predictors is provided in the bivariate MA(1) case. Furthermore, it is argued that the condition of equality of predictors as stated by Lütkepohl (Forecasting aggregated vector ARMA processes, Springer, Berlin, 1987) is only sufficient (not necessary) for the equality of mean squared errors. Finally, it is shown that the equality of forecasting accuracy for the two predictors can be achieved using specific assumptions on the parameters of the vector MA(1) structure.     

Choice and circumstance: Qualitative insights into contemporary childlessness in Australia

Using data from in-depth interviews with 115 women, men and couples in eastern Australia for whom family formation was a recent, current or imminent future issue, this article explores contemporary childlessness among those physically able to have children. It differentiates between those childless by choice and by circumstance, and among other themes highlights (i) the role preservation of lifestyle appears to play as a motive for deliberate childlessness following development of a life course through early adulthood that both generates lifestyle aspirations and often places parenthood on the backburner until after age 30, and (ii) the roles difficulty forming suitable relationships, women’s desire for meaningful careers, and male involvement in family formation decisions play in bringing about childlessness by circumstance.     

"He is everything": religion's role in the lives of immigrant youth

Using emergent theme analysis of qualitative interview data in combination with quantitative survey data, the role of religion in the lives of immigrant youth was explored. Latino, Haitian, and Chinese teenagers described, in their own rich words, the significance of religion to them; their responses are reflected in themes that point to the potential protective role of religion for some immigrant groups.     

Why Do They Start It? Explaining Reported Early-Teen Sexual Activity

This paper seeks an account of why young teens initiate consensual sexual activity. It does so by constructing statistical models aimed at distinguishing those who report having initiated sexual activity from those who have not in four samples of eighth graders from an Upstate New York county. Theoretical selection of the model variables is guided by insights from problem syndrome, control and differential association theories. From our findings we conclude the following: (1) Risk behaviors foreseen by the problem syndrome approach, including having used marijuana and having been drunk, are significant, powerful predictors of early-teen sexual activity. (2) The social setting of consensual sexual activity differs by sex at the eighth grade level. For example, having a boyfriend is a more consistent, powerful predictor variable for girls than is having a girlfriend for boys and there is evidence to support the hypothesis that boys initiate sexual activity in the context of status-seeking while girls are more likely to do so as a way of attaining approval. (3) Our findings do not give clear primacy to parents or peers as an influence on early-teen consensual sexual activity. Both control theory, usually associated with parental-influence variables, and differential association theory, usually associated with peer-influence variables, receive support. (4) The results of the research spanning a 2-year period of intensive community antiteen-pregnancy efforts by a Zero Adolescent Pregnancy (ZAP) campaign are consistent with the conclusion that such a multifaceted approach might help lower early-teen initiation of sexual activity.     

Does Distance Hinder Coordination? Identifying and Bridging Boundaries of Offshored Work

We submit that offshoring research focused mostly about an empirical phenomenon and extending our understanding about it, rather than expanding our understanding of the underlying theory as illuminated by empirical evidence. To theoretically frame the implications of offshoring strategy and practice for organizational design, this paper centers on the interplay between coordination and geographical distance. Distance strains the traditional approaches to coordination – i.e. decomposability and communication – as it impacts on knowledge boundaries created by the decomposition scheme. This increases the inherent complexity of the international division and coordination of innovative labor and knowledge and calls for new organizational practices.     

Use of propensity score matching to evaluate a national smoking cessation media campaign

Sustained mass media campaigns have been recommended to stem the tobacco epidemic in the United States. Propensity score matching (PSM) was used to estimate the effect of awareness of a national smoking cessation media campaign (EX) on quit attempts and cessation-related cognition. Participants were 4,067 smokers and recent quitters aged 18-49 in targeted U.S. media markets. Controlling for potential confounders through PSM and regression analysis, confirmed awareness of EX was not significantly associated with either outcome at 6-month follow-up. Matched analyses excluding 217 quitters resulted in a significant effect of EX on both outcomes.