Stability of dyadic exchange: Experimental evidence for the impact of shared group membership.

Pair stability refers to the extent to which exchange occurs between the same actors over time. In a stable pair, actors know what to expect of one another and have a sense of predictability as to the outcome of the exchange. When actors are split into discrete groups, shared group membership contributes to formation of new ties and maintenance of existing ties due to the mechanism of attraction to similar others. Using the formal framework of biased net theory, we propose three hypotheses which link shared group membership with the odds of pair stability. These hypotheses are tested against data from an experiment (N = 180) in which participants were first split into two groups and then given a series of opportunities to share resources with one another. Results of the experiment are consistent with the hypotheses.

Non-cognitive skills and social gaps in digital skills: Evidence from ICILS 2018.

Using data from the 2018 round of the International Computer and Literacy Survey (ICILS), this study looks at the effect of non-cognitive skills (e.g., motivation, ambition, and conscientiousness) on digital competences as measured by the Computer and Information Literacy (CIL) test score. Non-cognitive skills may be especially important in low-stakes tests such as ICILS, where students face no consequences - positive or negative - as a result of their performance. The empirical results show that several non-self-reported measures acting as proxies for non-cognitive skills are significant determinants of CIL test scores. Furthermore, the findings point at differences in non-cognitive skills across gender, immigrant background, and socioeconomic status. This suggests that one should be cautious when inferring about inequality in digital competences along these dimensions using low-stakes test scores, and underscores the importance of controlling for non-cognitive skills.

The effect of the COVID-19 disruption on the gender gap in students' performance: a cross-country analysis.

Background: This paper investigates how the COVID-19 school closure has affected the gender gap in grade-8 students' performance and what are the drivers behind this. By analysing four different countries (i.e., the Russian Federation, Slovenia, Uzbekistan and the United Arab Emirates), the paper represents the first study addressing the issue from a comparative perspective. Methods: The study uses data from the Responses to Educational Disruption Survey (REDS) survey, which comprises international comparable data on how students approached remote learning during the COVID-19 disruption. The extent of the gender gap is estimated by employing an ordered logit model, while the Karlson-Holm-Breen (KHB) decomposition method is used to analyse the different potential channels that could account for the gender gap during COVID-19. Results: The empirical results reveal that, during the COVID-19 school closure, girls tended to perceive changes in their learnings less favourably than boys, both in terms of improvement in self-perceived learning and self-reported improvement in grades-with odds of a more affirmative response between 20 and 25% lower for girls relative to boys. The main drivers explaining this gender gap are physical activity and psychological distress of students during the COVID-19 disruption, as well as the perceived family climate. Conclusions: The paper shows systematic gender differences in how students perceived their educational outcomes changed due to the COVID-19 disruption, providing evidence on the factors driving these differences. The findings could be employed to design policy actions aimed at increasing gender equality in education.

Intergenerational mobility and omnivorism in eating.

Drawing on three hypotheses concerned with cultural consequences of social mobility, we investigate whether intergenerational class mobility influences omnivorism in eating, regarded as a new dimension of lifestyle. Using data from a national survey carried out in Poland in 2013 and diagonal reference models, we find most support for the hypothesis of maximization saying that upward mobility encourages conformity to the habits of the class of destination. It shows that in Poland, as in other societies, the upwardly mobile tend to align their behaviour with that of their highest status reference group. Accordingly, the downwardly mobile representatives of the top category conform more to the norms of the class of origin than those of the destination class. At the same time, individuals who experience intergenerational inflow to the highest managerial and professional categories display higher levels of highbrow tastes than their non-mobile counterparts from the origin classes. Contrary to the thesis about replacement of traditional class barriers by omnivorism we see that the omnivore/univore divide does not obliterate the highbrow/lowbrow one.

Hydrodechlorination of Tetrachloromethane over Palladium Catalysts Supported on Mixed MgF2-MgO Carriers.

Pd/MgO, Pd/MgF2 and Pd/MgO-MgF2 catalysts were investigated in the reaction of CCl4 hydrodechlorination. All the catalysts deactivated in time on stream, but the degree of deactivation varied from catalyst to catalyst. The MgF2-supported palladium with relatively large metal particles appeared the best catalyst, characterized by good activity and selectivity to C2-C5 hydrocarbons. Investigation of post-reaction catalyst samples allowed to find several details associated with the working state of hydrodechlorination catalysts. The role of support acidity was quite complex. On the one hand, a definite, although not very high Lewis acidity of MgF2 is beneficial for shaping high activity of palladium catalysts. The MgO-MgF2 support characterized by stronger Lewis acidity than MgF2 contributes to very good catalytic activity for a relatively long reaction period (~5 h) but subsequent neutralization of stronger acid centers (by coking) eliminates them from the catalyst. On the other hand, the role of acidity evolution, which takes place when basic supports (like MgO) are chlorided during HdCl reactions, is difficult to assess because different events associated with distribution of chlorided support species, leading to partial or even full blocking of the surface of palladium, which plays the role of active component in HdCl reactions.