Estimating models based on Markov jump processes given fragmented observation series

We consider the problem of estimating the rate matrix governing a finite-state Markov jump process given a number of fragmented time series. We propose to concatenate the observed series and to employ the emerging non-Markov process for estimation. We describe the bias arising if standard methods for Markov processes are used for the concatenated process, and provide a post-processing method to correct for this bias. This method applies to discrete-time Markov chains and to more general models based on Markov jump processes where the underlying state process is not observed directly. This is demonstrated in detail for a Markov switching model. We provide applications to simulated time series and to financial market data, where estimators resulting from maximum likelihood methods and Markov chain Monte Carlo sampling are improved using the presented correction.     

Prevalence and reasons for Juul use among college students

Abstract

Objective: Examine Juul use patterns, sociodemographic and personal factors associated with Juul use, and reasons for Juul initiation and current use, among college students. Participants: Convenience sample of 371 undergraduates at a large university in the southeast; recruited April 2018. Methods: Cross-sectional design using an online survey. Logistic regression identified the personal risk factors for current use. Results: Over 80% of participants recognized Juul; 36% reported ever use and 21% past 30-day use. Significant risk factors for current Juul use were: male, White/non-Hispanic, lower undergraduate, and current cigarette smoker. Current Juul users chose ease of use and lack of a bad smell as reasons for use. Ever Juul users most commonly endorsed curiosity and use by friends as reasons for trying Juul. Conclusions: Given the propensity for nicotine addiction among youth and young adults, rates of Juul use are alarming and warrant immediate intervention.     

The compensation of non-executive directors: rationale,form, and findings

Corporate governance guidelines in many countries do not specify the determinants of non-executive director compensation and the empirical evidence has only briefly and indirectly addressed this issue. We show that this question is fundamentally complex because (a) whilst the roles of non-executive directors are relatively well stated, their actual contributions remain unclear, (b) governance codes have not discussed the ways in which non-executive directors should undertake their roles and (c) non-executive director contribution may be unobservable. As a result, their efforts, contribution and/or performance are difficult to measure. Nevertheless, we find the literature related to non-executive directors strongly supportive of some sort of remuneration that is a function of performance and effort to align non-executive directors with their duties and make boards more efficient in undertaking their duties.     

The effect of female education on marital matches and child health in Bangladesh

This paper examines the effects of female education on marriage outcomes by exploiting the exogenous variation generated by the Female Secondary School Stipend Program in Bangladesh, which made secondary education free for rural girls. Our findings show that an additional year of female education leads to an increase in 0.72 years of husband’s education and that better educated women pair with spouses who have better occupations and are closer in age to their own, suggesting assortative mating. Those educated women appear to experience greater autonomy in making decisions on receiving their own health care and visiting their family. Furthermore, educated women have lower fertility and use more maternal health care, and their children have better health outcomes than those of less-educated women. Overall, our results suggest that the marriage market is one of the channels through which women’s education affects their life outcomes.     

Social bonding and loneliness after network disruption: A longitudinal study of East German refugees

After the 1989 breakdown of the communist system, 235 East Germans were interviewed three times during the two years following their transition to West Berlin. In moving to the west, the migrants had to deal with various stressors, among them the lack of social ties in their new environment. Fortunately, the number of their new friends increased steadily, and loneliness declined. These changes, however, differed between sexes and age groups. Men made more friends than women, in particular same-sex friends, whereas women knitted ties with both sexes. The young built larger networks than the intermediate age group. Loneliness emerged as an inhibiting factor in the bonding process. The study demonstrates how well these refugees coped with a social crisis. It also examines the roles that loneliness and social bonding played in the readjustment process.     

What Affects the Quality of Economic Analysis for Life‐Saving Investments?‡

Economic analysis of life-saving investments in both the public and private sectors has the potential to dramatically improve longevity and the quality of life, but only if the analyses on which decisions are based are done well. In this article, we analyze a data set that provides information on the content and quality of journal articles that measure the cost-effectiveness of life-saving investments. Our study is the first to provide a detailed multivariate analysis of factors affecting objective measures of quality. We also explore whether a series of recommendations by an expert panel convened by the U.S. Public Health Service affect the way analyses of specific life-saving investments are done. Our results suggest that four factors are positively correlated with an index we construct to measure analytical quality: (1) having at least one author affiliated with a university, (2) publication in a journal that has experience in publishing these analyses, (3) if the life-saving investment is located in the United States, and (4) if the analysis considers a measure of social costs or benefits. Somewhat surprisingly, a study's funding source and whether it is affiliated with industry are not significantly correlated with the quality index. Finally, neither time nor the panel guidelines had an impact on the index.