RESEARCH

This paper studies changes in the political polarization in the aftermath of a shock on a politically divisive topic. I construct a measure of political polarization based on the speeches of the US Representatives. Relying on the exogenous feature of a mass shooting event (MSE), I implement a dynamic difference-in-differences design exploiting variation across places and time. First, I document that MSE significantly increases the polarization on the gun rights topic. Second, I explore how these results are not limited to this political theme. In fact, the distance between Democrats and Republicans increases over a range of different topics, revealing how contagious polarization may be. I investigate and discuss different mechanisms which may explain these findings. I focus on describing which politicians talk, in which terms and about what topics, following a salient event. Finally, I discuss how the increase in polarization impacts the democratic process. In the days following an MSE, the probability of voting and passing a new law in the House of Representative decreases. These effects are long lasting: policies voted after such divisive events are also less likely to be voted and passed in the future.

This paper shows that political rhetoric can influence the behavior of law enforcement officers. We follow monthly arrests for 1383 police agencies in 40 American States from January 1984 to December 1990. During these years the Presidents of the United States developed a strong rhetoric against drug abuse, targeting crack cocaine, a drug that the media associated with Blacks. We implement both a difference in differences and a reduced-form-Bartik-type approach to test if exposure to the presidential rhetoric affected the behavior of law enforcement officers. In counties with heightened exposure to presidential rhetoric against drug abuse, arrests for drug possession among Blacks increased significantly, while no such effect was observed for Whites. We provide evidence that the presidential rhetoric changed attitudes towards minorities and that the effect is entirely driven by areas with low historical racial resentment. These findings suggest that political rhetoric is at the root of institutional discrimination in arrests for drugs. 

We study how population ageing interacts with voters’ representation, engagement with politics, and the content of political agendas. Leveraging the European Social Survey, we observe that over the past two decades, individuals under the age of 50 have become a minority within the voter population. This shift has been exacerbated by a decline in the turnout propensity of those under 50, juxtaposed with an increase among older age groups. The evolution of turnout propensity has unfolded gradually across cohorts: each successive cohort entering the eligible voter population has exhibited lower turnout rates compared to its predecessors and has failed to converge to previous levels throughout its lifecycle. Moreover, these dynamics have coincided with a shift in the political agenda. Through an analysis of political manifestos, we demonstrate a switch towards topics appealing to older voters, notably retirement policies. 

With Nicola Mastrorocco (University of Bologna) and Arianna Ornaghi (Hertie School)

With Nicola Fontana (Trinity College Dublin) and Nicola Mastrorocco (University of Bologna)