Joint models for mixed categorical outcomes: a study of HIV risk perception and disease status in Mozambique

Two types of bivariate models for categorical response variables are introduced to deal with special categories such as ‘unsure’ or ‘unknown’ in combination with other ordinal categories, while taking additional hierarchical data structures into account. The latter is achieved by the use of different covariance structures for a trivariate random effect. The models are applied to data from the INSIDA survey, where interest goes to the effect of covariates on the association between HIV risk perception (quadrinomial with an ‘unknown risk’ category) and HIV infection status (binary). The final model combines continuation-ratio with cumulative link logits for the risk perception, together with partly correlated and partly shared trivariate random effects for the household level. The results indicate that only age has a significant effect on the association between HIV risk perception and infection status. The proposed models may be useful in various fields of application such as social and biomedical sciences, epidemiology and public health.     

Weighted simulated integrated conditional moment tests for parametric conditional distributions of stationary time series processes

In this article, we propose a weighted simulated integrated conditional moment (WSICM) test of the validity of parametric specifications of conditional distribution models for stationary time series data, by combining the weighted integrated conditional moment (ICM) test of Bierens (1984 Bierens, H. J. (1984). Model specification testing of time series regressions. Journal of Econometrics 26:323–353.[Crossref], [Web of Science ®] , [Google Scholar]) for time series regression models with the simulated ICM test of Bierens and Wang (2012 Bierens, H. J., Wang, L. (2012). Integrated conditional moment tests for parametric conditional distributions. Econometric Theory 28:328–362.[Crossref], [Web of Science ®] , [Google Scholar]) of conditional distribution models for cross-section data. To the best of our knowledge, no other consistent test for parametric conditional time series distributions has been proposed yet in the literature, despite consistency claims made by some authors.     

Income inequality and participation: A comparison of 24 European countries

Previous research suggests that when there is a high level of inequality, there is a low rate of participation. Two arguments are generally offered: First, inequality depresses participation because people from different status groups have fewer opportunities to share common goals. Second, people may participate more in civic and social life when they have more resources. However, until now, these explanations have not been separated empirically. Using EU-SILC data for 24 European countries, we analyze how income inequality is related to civic and social participation. Our results indicate that the main effects of inequality manifest via resources at the individual and societal level. However, independent of these resources, higher inequality is associated with lower civic participation. Furthermore, inequality magnifies the relationship between income and participation. This finding is in line with the view that inter-individual processes explain why inequality diminishes participation.     

Skill and education effects on earnings in 18 Countries: The role of national educational institutions

This study investigates whether the mechanisms why education is rewarded vary across countries. Do educational institutions affect the likelihood that support for a particular mechanism is found? Combining IALS survey data and OECD statistics on educational institutions, it was shown that the effect of measured skill on earnings - controlled for educational attainment - is lower in countries where educational institutions produce skills relevant for work through the vocational system. This indicates that the human capital perspective on education works particularly well in vocationally oriented educational systems, as the skills generated in education are strongly overlapping with the skills that are rewarded. An alternative mechanism sees education as a means for social closure through credentialization. Under the credentialization model, education is not primarily rewarded for the productivity-enhancing skills it entails, but rather for reasons unrelated to productivity. Following this theory education is used for selection into the organization, after which directly observable skills are determining wages. Assuming that a strongly differentiated educational system creates boundaries between social groups, it is hypothesized that strongly differentiated systems lead to stronger measured skill effects. We do not find support for this hypothesis.     

In Search of the Optimum Harvey Wallbanger Recipe via Mixture Experiment Techniques

A Harvey Wallbanger is an alcoholic drink composed of three ingredients: orange juice, vodka, and Galliano. One of the authors (Sahrmann), a connoisseur of the libation, was perplexed upon discovering that different bartender handbooks listed different recipes for the drink. Determined to shed some light on this irksome problem, he issued invitations for an evening workshop session (party) to former and current attendees of an experimental-design training course taught within his company. A mixture experiment was designed and data collected using the class participants. This article describes the experimental design and the analysis of the data. The results of the experiment indicate that reducing the proportion of vodka produces better-flavored drinks. The results of the experiment were not entirely conclusive, however, so recommendations are made for future experimentation.     

论文明的发展趋势——生态文明

从属于地球共同体的人类文明走过了原始文明、农业文明,又演绎出今天的现代全球文明。现代文明的缺陷引起地球共同体终结的危机。因此人类文明需要进入新的发展过程,而走向生态文明就是人类和地球共同体的未来,这需要克服实证科学语言所具有的单一性,以东方占优势的类比思维来弥补西方实证科学逻辑思维的不足。无论是东方文明还是西方文明,都有着相互的关联。西方的逻辑、东方的关联和类比,都是走向生态文明的必须。