Waiting to score. Conversion probability and the video assistant referee (VAR) in football penalty kicks.

The VAR has introduced a new element to football. Before, a decision to award a penalty kick could not be reversed. The player taking the penalty could take it relatively quickly after the referee called the foul. After the introduction of the VAR, every penalty kick decision is replayed by the VAR and also quite often reviewed on-field. As a consequence, time between the initial decision by the referee and the actual penalty kick has increased substantially. We examined the influence of the time-interval duration between the foul and the actual penalty kick on the conversion probability using a logit model. Also, we assessed the consequences of a VAR intervention, if any. We used data on all 2888 penalties awarded in top leagues in England, Spain, Germany, Italy, the Netherlands, and the UEFA Champions League, over the course of five seasons (2015/2016-2019/2020). We found that the duration between the foul and the moment the penalty is taken does not impact the conversion probability. However, whether or not the VAR intervenes with the referee's decision has a negative effect on the conversion probability of penalty kicks. Football teams and coaches should incorporate this element of uncertainty in training.

Online activity of mosques and Muslims in the Netherlands: A study of Facebook, Instagram, YouTube and Twitter.

Research on Muslim minorities in western societies has mainly focused on offline behavior, such as mosque attendance, whereas little is known about their presence in the online world. This study explores the online visibility and activities of all (478) mosques in the Netherlands. We collected data on personal websites and four social media platforms (Facebook, Twitter, Instagram and YouTube). The majority of mosques have a website (52%) and an account on Facebook (61%). Less often used are Twitter (17%), Instagram (17%) and YouTube (19%). On social media platforms, mosques strongly differ in their activity and number of followers. We find evidence to suggest that Salafist mosques, which tend to have a strict ideology, are more active on Twitter and YouTube, and also attract a larger share of followers on Facebook than non-Salafist mosques. Our more fine-grained analysis on Twitter shows that Salafist mosques in the Netherlands cluster together. Followers of Salafist mosques make up a community of users who are mainly connected to each other ("bonding ties"), and much less so to other users ("bridging ties"). We conclude with a discussion of opportunities for studying the online presence and activities of mosques and Muslims in western societies.

A global analysis of the impact of COVID-19 stay-at-home restrictions on crime.

The stay-at-home restrictions to control the spread of COVID-19 led to unparalleled sudden change in daily life, but it is unclear how they affected urban crime globally. We collected data on daily counts of crime in 27 cities across 23 countries in the Americas, Europe, the Middle East and Asia. We conducted interrupted time series analyses to assess the impact of stay-at-home restrictions on different types of crime in each city. Our findings show that the stay-at-home policies were associated with a considerable drop in urban crime, but with substantial variation across cities and types of crime. Meta-regression results showed that more stringent restrictions over movement in public space were predictive of larger declines in crime.