Our research hypothesis is that space restriction on social media communication creates fertile ground for aggressive, insulting and apodictic (AIA) speech thereby deteriorating the political debate and enhancing polarisation, violence and populism. We test our hypothesis by using as identification mechanism the decision of Twitter to double tweets’ length (from 140 to 280 characters) since November the 7th 2017. We use a machine learning classification approach and find with a discontinuity design diff-in-diff estimate that the event significantly and markedly reduced likes and retweets of aggressive, insulting and apodictic tweets in the political domain in the three-day interval around the policy change. Falsification tests show that our result is not spurious and the reduction in the share of aggressive, insulting and apodictic replies to a given political tweet after the character count change goes in support of our hypothesis. Our conclusion is that the Twitter reform has reduced attractiveness of aggressive speech thereby making the social media platform a less fertile ground for polarisation.

We define generativity as the combination of creativity and care for others wellbeing. Based on John Stuart Mill, Robert Kennedy and Antonio Genovesi quotes we test several research hypotheses on the available waves of the European Social Survey and find that generativity is associated positively and significantly with subjective wellbeing (under the different dimensions of life satisfaction and positive affect), resilience, interpersonal trust, active citizenship and participation to political elections. Our findings are robust across survey waves, gender, age, education splits and significant in estimates considering only individuals living in the same country. With an IV approach we provide evidence that the investigated nexus hides a direct causality link from all our the dependent variables.

We test the effect of the first wave COVID-19 lockdown on quality of air across Italian municipalities. We show that lockdown measures, as expected, reduced outdoor (car transit and workplace) mobility, while increasing (indoor) residential stay. We expect the first effect to contribute to better quality of air, although counterbalanced by the second due to increased heating at home. Our findings are consistent with this hypothesis, since the combined effect of lockdown measures on particulate matter concentration is nonlinear and determined by the interplay of two exogenous shocks (the lockdown decision and the nonsynchronous centralised heating halt in Italian climatic zones). More specifically, in the first lockdown month the increase in house heating generated an abnormal rise in particulate matter concentration with respect to the corresponding months of the previous years. The effect was reversed in the following two months when centralized heating halted. Evidence of the lockdown effects on mobility is consistent with the lockdown effect on outdoor mobility since we observe a significant fall in nitrogen dioxide. Policy implications of our paper is that higher ecological sustainability of heating and mobility can reduce the trade-off between economic/social activity and environmental sustainability.

In Italy, 23 percent of the 7,903 municipalities include protected areas, while 6.4 percent (which we define as park municipalities) national parks. We investigate the relationship between park areas and quality of air and find that park municipalities experienced far lower levels of air pollution in the last three years, the gross difference ranging from 25 to 30 percent lower levels of particulate matter (PM10 and PM2.5) and three times lower levels of nitrogen dioxide. In our econometric analysis we find that part (but not all) of this difference depends on the lower population density and manufacturing activity in municipalities with national parks. We as well show that park municipalities have progressively reduced particulate matter over the last three years and that parks have a “green lung” function since, in non-park municipalities, air pollution grows in the distance from national parks. Based on our average of estimated parameters of the impact of the main air pollutants on mortality in the literature we calculate that living in park municipalities reduces mortality rates by around 10 percent.