News coverage of local crime influences police behaviour: US municipalities exposed to a 27% reduction in the probability of appearing in the news with a local crime story experience an 8% decline in their violent crime clearance rate with respect to municipalities not exposed to the change.
This is the main finding of new research by Nicola Mastrorocco and Arianna Ornaghi, to be presented at the annual congress of the European Economic Association in August 2020.
Law enforcement is one of the most important functions of US local governments, but we still have a limited understanding of what forces shape the incentive structure of police departments (Owens, 2020). Considering the strong crime focus of local news (see Figure I), local media is uniquely positioned to play a role in influencing the behaviour of police officers.
Studying the relationship between local media coverage of crime and policing is challenging as the two might be jointly determined. To overcome this problem, we need a shock to media content that is unrelated to changes in police behaviour. For this, the authors exploit the fact that in the last ten years, the local TV market in the United States has seen an increase in concentration driven by large broadcast groups acquiring high numbers of local TV stations, and acquisitions are likely to affect content (Stahl, 2016). They focus on the most active player in the local TV station market: Sinclair.
Sinclair acquisitions affect content in two ways. First, Sinclair reduces local news coverage in favour of a national focus (Martin and McCrain (2020)). Second, Sinclair – a right-leaning media group – also introduces more conservative content overall. To isolate the effect of the first change in content (i.e. the effect of a change in local news coverage), the authors make use of the fact that while all municipalities in a media market are exposed to the conservative message of Sinclair, only some municipalities experience shocks to the probability of being in the news.
In particular, the decline in coverage driven by acquisitions only matters for municipalities that are likely to appear in the news in the first place (covered municipalities). Instead, municipalities that are never in the news should not experience a change in their local coverage (non-covered municipalities). As a result, it is possible to estimate the effect of the decline in news coverage of a municipality’s crime by focusing on the relative effect of a Sinclair acquisition on covered and non-covered municipalities.
The study then proceeds in two steps.
First, it shows that ownership matters for content. Using a novel dataset that includes 9.5 million stories part of 300,000 newscasts, the study shows that once acquired by Sinclair, TV stations decrease news coverage of local crime. In particular, covered municipalities are 27% less likely to be mentioned in a crime story after a station gets acquired by Sinclair with respect to non-covered municipalities.
Second, the study shows that the decline in news coverage of local crime matters for policing: after Sinclair enters a media market, covered municipalities experience 3.9 percentage points lower violent crime clearance rates with respect to non-covered municipalities, which corresponds to 8% of the baseline mean.
In contrast, property crime clearance rates do not experience a similar decline. This heterogeneity can be explained by the fact that local TV news have a clear violent crime focus. As Figure II shows, 75% of local crime stories are about a violent crime and only 16.7% are about a property crime, a difference that is even starker considering that property crimes are more common by orders of magnitude.
Why does the decline in news coverage of local crime affect clearance rates? The authors propose the following explanation. The decrease in local crime coverage affects individuals’ perceptions of crime, which becomes less salient for local citizens. This in turn reduces the pressure that citizens put on the police to solve these crimes, causing police officers to reallocate their effort away from clearing these types of crime in favour of other policing-related activities.
References
Martin, Gregory J and McCrain, Joshua. 2018. ‘Local News and National Politics’, American Political Science Review pp. 1–13.
Mastrorocco, Nicola and Ornaghi, Arianna. 2020. Who Watches the Watchmen? Local News and Police Behaviour in the United States. Working Paper.
Owens, Emily. 2020, The Economics of Policing, in Dave Marcotte and Klaus Zimmerman., eds, ‘The Economics of Risky Behaviour’, Springer.
Stahl, Jessica Calfee. 2016. ‘Effects of Deregulation and Consolidation of the Broadcast Television Industry’, American Economic Review 106(8), 2185–2218.
Contact
Nicola Mastrorocco
Trinity College Dublin
Twitter: @mastrorocconick
Arianna Ornaghi
University of Warwick
http://www.ariannaornaghi.com/
Twitter: @ariannaornaghi