Differential impact of physical distancing strategies on social contacts relevant for the spread of SARS-CoV-2: evidence from a cross-national online survey, March-April 2020.

OBJECTIVES: We investigate changes in social contact patterns following the gradual introduction of non-pharmaceutical interventions and their implications for infection transmission in the early phase of the pandemic. DESIGN, SETTING AND PARTICIPANTS: We conducted an online survey based on targeted Facebook advertising campaigns across eight countries (Belgium, France, Germany, Italy, the Netherlands, Spain, UK and USA), achieving a sample of 51 233 questionnaires in the period 13 March-12 April 2020. Poststratification weights based on census information were produced to correct for selection bias. OUTCOME MEASURES: Participants provided data on social contact numbers, adoption of protective behaviours and perceived level of threat. These data were combined to derive a weekly index of infection transmission, the net reproduction number [Formula: see text] . RESULTS: Evidence from the USA and UK showed that the number of daily contacts mainly decreased after governments issued the first physical distancing guidelines. In mid-April, daily social contact numbers had decreased between 61% in Germany and 87% in Italy with respect to pre-COVID-19 levels, mostly due to a contraction in contacts outside the home. Such reductions, which were uniform across age groups, were compatible with an [Formula: see text] equal or smaller than one in all countries, except Germany. This indicates lower levels of infection transmission, especially in a period of gradual increase in the adoption rate of the face mask outside the home. CONCLUSIONS: We provided a comparable set of statistics on social contact patterns during the COVID-19 pandemic for eight high-income countries, disaggregated by week and other demographic factors, which could be leveraged by the scientific community for developing more realistic epidemic models of COVID-19.

Rapid Review of Social Contact Patterns During the COVID-19 Pandemic.

BACKGROUND: Physical distancing measures aim to reduce person-to-person contact, a key driver of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. In response to unprecedented restrictions on human contact during the coronavirus disease 2019 (COVID-19) pandemic, studies measured social contact patterns under the implementation of physical distancing measures. This rapid review synthesizes empirical data on the changing social contact patterns during the COVID-19 pandemic. METHOD: We conducted a systematic review using PubMed, Medline, Embase, and Google Scholar following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We descriptively compared the distribution of contacts observed during the pandemic to pre-COVID data across countries to explore changes in contact patterns during physical distancing measures. RESULTS: We identified 12 studies reporting social contact patterns during the COVID-19 pandemic. Eight studies were conducted in European countries and eleven collected data during the initial mitigation period in the spring of 2020 marked by government-declared lockdowns. Some studies collected additional data after relaxation of initial mitigation. Most study settings reported a mean of between 2 and 5 contacts per person per day, a substantial reduction compared to pre-COVID rates, which ranged from 7 to 26 contacts per day. This reduction was pronounced for contacts outside of the home. Consequently, levels of assortative mixing by age substantially declined. After relaxation of initial mitigation, mean contact rates increased but did not return to pre-COVID levels. Increases in contacts post-relaxation were driven by working-age adults. CONCLUSION: Information on changes in contact patterns during physical distancing measures can guide more realistic representations of contact patterns in mathematical models for SARS-CoV-2 transmission.

Behaviours and attitudes in response to the COVID-19 pandemic: insights from a cross-national Facebook survey.

BACKGROUND: In the absence of medical treatment and vaccination, individual behaviours are key to curbing the spread of COVID-19. Here we describe efforts to collect attitudinal and behavioural data and disseminate insights to increase situational awareness and inform interventions. METHODS: We developed a rapid data collection and monitoring system based on a cross-national online survey, the "COVID-19 Health Behavior Survey". Respondent recruitment occurred via targeted Facebook advertisements in Belgium, France, Germany, Italy, the Netherlands, Spain, the United Kingdom, and the United States. We investigated how the threat perceptions of COVID-19, the confidence in the preparedness of organisations to deal with the pandemic, and the adoption of preventive and social distancing behaviours are associated with respondents' demographic characteristics. RESULTS: We analysed 71,612 questionnaires collected between March 13-April 19, 2020. We found substantial spatio-temporal heterogeneity across countries at different stages of the pandemic and with different control strategies in place. Respondents rapidly adopted the use of face masks when they were not yet mandatory. We observed a clear pattern in threat perceptions, sharply increasing from a personal level to national and global levels. Although personal threat perceptions were comparatively low, all respondents significantly increased hand hygiene. We found gender-specific patterns: women showed higher threat perceptions, lower confidence in the healthcare system, and were more likely to adopt preventive behaviours. Finally, we also found that older people perceived higher threat to themselves, while all respondents were strongly concerned about their family. CONCLUSIONS: Rapid population surveys conducted via Facebook allow us to monitor behavioural changes, adoption of protective measures, and compliance with recommended practices. As the pandemic progresses and new waves of infections are a threatening reality, timely insights from behavioural and attitudinal data are crucial to guide the decision-making process. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1140/epjds/s13688-021-00270-1.

Addressing Public Health Emergencies via Facebook Surveys: Advantages, Challenges, and Practical Considerations.

Surveys of the general population can provide crucial information for designing effective nonpharmaceutical interventions to tackle public health emergencies, such as the COVID-19 pandemic. Yet, conducting such surveys can be difficult, especially when timely data collection is required. In this viewpoint paper, we discuss our experiences with using targeted Facebook advertising campaigns to address these difficulties in relation to the COVID-19 pandemic. We describe central advantages, challenges, and practical considerations. This includes a discussion of potential sources of bias and how they can be addressed.

The Gender Cliff in the Relative Contribution to the Household Income: Insights from Modelling Marriage Markets in 27 European Countries.

In Western countries, the distribution of relative incomes within marriages tends to be skewed in a remarkable way. Husbands usually do not only earn more than their female partners, but there is also a striking discontinuity in their relative contributions to the household income at the 50/50 point: many wives contribute just a bit less than or as much as their husbands, but few contribute more. This 'cliff' has been interpreted as evidence that men and women avoid situations where a wife would earn more than her husband, since this would go against traditional gender norms. In this paper, we use a simulation approach to model marriage markets and demonstrate that a cliff in the relative income distribution can also emerge without such avoidance. We feed our simulations with income data from 27 European countries. Results show that a cliff can emerge from inequalities in men's and women's average incomes, even if they do not attach special meaning to a situation in which a wife earns more than her husband.

The reversal of the gender gap in education and relative divorce risks: A matter of alternatives in partner choice?

Recent evidence from the United States suggests that the reversal of the gender gap in education was associated with changes in relative divorce risks: hypogamous marriages, where the wife was more educated than the husband, used to have a higher divorce risk than hypergamous marriages, where the husband was more educated, but this difference has disappeared. One interpretation holds that this may result from cultural change, involving increasing social acceptance of hypogamy. We propose an alternative mechanism that need not presuppose cultural change: the gender-gap reversal in education has changed the availability of alternatives from which highly educated women and men can choose new partners. This may have lowered the likelihood of women leaving husbands with less education and encouraged men to leave less educated spouses. We applied an agent-based model to twelve European national marriage markets to illustrate that this could be sufficient to create a convergence in divorce risks.

Status inconsistency in groups: How discrepancies between instrumental and expressive status result in symptoms of stress.

This study examines whether a mismatch between the positions that individuals hold in different status hierarchies results in symptoms of stress. Prior research has focused on inconsistencies between socioeconomic status dimensions (e.g., education and income) and did not find a significant relation between status inconsistency and stress. In this paper, we build on research on role differentiation and propose to study the effect of inconsistencies between instrumental status and expressive status in group contexts. We hypothesize that people with an inconsistency between these status dimensions experience feelings of uncertainty and frustration in their interactions with others and this manifests in stress-related symptoms. We test this hypothesis with data collected in a medium-sized Dutch childcare organization (N = 93). Polynomial regression analysis, visualized in response surface plots, suggests that status inconsistent employees report higher levels of stress.

The Reversed Gender Gap in Education and Assortative Mating in Europe.

While in the past men received more education than women, the gender gap in education has turned around: in recent years, more highly educated women than highly educated men are reaching the reproductive ages. Using data from the European Social Survey (rounds 1-6), we investigate the implications of this reversed gender gap for educational assortative mating. We fit multilevel multinomial regression models to predict the proportions of men and women living with a partner of a given level of education, contingent on respondents' own educational attainment and on the cohort-specific sex ratio among the population with tertiary education at the country level. We find that highly educated women tend to partner more often "downwards" with less educated men, rather than remaining single more often. Medium educated women are found to partner less often "upwards" with highly educated men. For men, there is no evidence that they are more likely to partner with highly educated women. Rather, they are found to be living single more often. In sum, women's advantage in higher education has affected mating patterns in important ways: while women previously tended to form unions with men who were at least as highly educated as themselves, they now tend to live with men who are at most as highly educated. Along the way, advanced education became a bonus on the mating market for women as well as for men.

Status Perceptions Matter: Understanding Disliking Among Adolescents.

The emergence of disliking relations depends on how adolescents perceive the relative informal status of their peers. This phenomenon is examined on a longitudinal sample using dynamic network analysis (585 students across 16 classes in five schools). As hypothesized, individuals dislike those who they look down on (disdain), and conform to others by disliking those who they perceive as being looked down on by their peers (conformity). The inconsistency between status perceptions also leads to disliking, when individuals do not look up to those who they perceive to be admired by peers (frustration). Adolescents are not more likely to dislike those who they look up to (admiration). The results demonstrate the role of status perceptions on disliking tie formation.

Assortative mating and the reversal of gender inequality in education in europe: an agent-based model.

While men have always received more education than women in the past, this gender imbalance in education has turned around in large parts of the world. In many countries, women now excel men in terms of participation and success in higher education. This implies that, for the first time in history, there are more highly educated women than men reaching the reproductive ages and looking for a partner. We develop an agent-based computational model that explicates the mechanisms that may have linked the reversal of gender inequality in education with observed changes in educational assortative mating. Our model builds on the notion that individuals search for spouses in a marriage market and evaluate potential candidates based on preferences. Based on insights from earlier research, we assume that men and women prefer partners with similar educational attainment and high earnings prospects, that women tend to prefer men who are somewhat older than themselves, and that men prefer women who are in their mid-twenties. We also incorporate the insight that the educational system structures meeting opportunities on the marriage market. We assess the explanatory power of our model with systematic computational experiments, in which we simulate marriage market dynamics in 12 European countries among individuals born between 1921 and 2012. In these experiments, we make use of realistic agent populations in terms of educational attainment and earnings prospects and validate model outcomes with data from the European Social Survey. We demonstrate that the observed changes in educational assortative mating can be explained without any change in male or female preferences. We argue that our model provides a useful computational laboratory to explore and quantify the implications of scenarios for the future.