This article is published in British Academy Review No. 37 (December 2021).
Dr Nicola Mastrorocco is Assistant Professor of Economics at Trinity College Dublin. Dr Arianna Ornaghi was awarded a Postdoctoral Fellowship in 2018 and is now Assistant Professor of Economics at the Hertie School.
Law enforcement is one of the most important functions of US local governments, but we still have a limited understanding of how the police respond to the broader civil society. In our research, we investigate whether local media might have a role to play in this respect. Focusing on municipal police departments in the United States, we ask how local TV news coverage of a municipality’s crime impacts policing.
The outcome that we study are clearance rates: crimes for which an offender is identified, over total number of crimes. Clearance rates are highly sensitive to what resources are allocated to investigations. As a result, they have often been used to study policing and are especially interesting in our setting, as they allow us to consider whether the types of crimes that get prioritised by the police department are affected by news coverage.
Identifying the relationship between news coverage of local crime and policing
The major challenge to studying the relationship between news coverage of local crime and policing is what economists and statisticians define as a simultaneous causality problem: that is, a situation in which two variables influence each other at the same time in the opposite direction. Is it local crime reporting that affects clearance rates or is it the other way around, with local news reporting causing low clearance rates? By simply estimating the relationship between news coverage of local crime and clearance rates, we would not be able to distinguish between these two distinct stories. In our research, we get around this issue by exploiting changes in content that are unlikely to be related to what is happening to clearance rates: changes due to acquisitions of local TV stations by a large broadcast group, Sinclair.
Based on anecdotal evidence and existing research, we know that Sinclair acquisitions affect content in two ways. First, Sinclair reduces local news coverage in favour of a national focus. This is the change in content that we are interested in studying. Second, Sinclair – a politically right-leaning media group – also introduces more conservative content overall. To control for this overall change in content and ensure that it is not driving our results, we 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 changes in the probability of being in the news.
In particular, the decline in coverage driven by Sinclair acquisitions should only matter for areas that are likely to appear in the news in the first place, which we call covered municipalities. Areas which are never in the news, that we call non-covered municipalities, should not experience a change in the coverage of local crime. As a result, we can 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.
Crimes in the news after acquisitions
We document how Sinclair acquisitions impact news coverage of local crime using a novel dataset that includes the transcripts of 8.5 million stories in 300,000 newscasts. We found that, once acquired by Sinclair, TV stations decrease news coverage of local crime. In particular, covered municipalities experience a large decline in the probability of appearing in the news with a crime story. The probability that a crime happening in a non-covered municipality is talked about in the news is not impacted. Overall, covered municipalities are 25 per cent less likely to be mentioned in a crime story after a station gets acquired by Sinclair, with respect to non-covered municipalities.
‘91% of local crime stories are about violent crime’
How does the decline in TV news coverage of local crime affect clearance rates?
Our main finding is that after Sinclair enters a media market, covered municipalities experience 3.4 percentage points lower violent crime clearance rates with respect to non-covered municipalities, which corresponds to 7.5 per cent of the baseline mean and approximately three fewer violent clearances.
In contrast, property crime clearance rates do not experience a similar decline. The difference across crime types can be explained by the fact that local TV news has a clear violent crime focus. As Figure I shows, 91 per cent of local crime stories are about a violent crime and only 17 per cent are about a property crime and about 8 per cent are both; a difference that is even starker if we consider that property crimes are more common by orders of magnitude.
Figure I: News coverage of local violent and property crimes
Notes: This figure shows what crimes are covered in local TV news. Panel (a) shows the average share of a municipality’s crime stories that are about violent crimes (i.e. murder, assault, rape, and robbery) and property crimes (i.e. burglary, theft, and motor vehicle theft). Panel (b) shows the average number of crime stories per reported offense across municipalities. In both graphs, the sample is restricted to 2010 and to media market that never experience Sinclair entry.
Public opinion and political pressure
A possible explanation for our findings is that the decline in news coverage of local crime affects the salience of crime as an issue in public opinion and the political pressure put on the police department. When stories about a municipality’s violent crimes are less frequent, crime becomes less salient in the eyes of local citizens. As a result, the police find themselves operating in a political environment where there is less pressure to tackle the problem of violent crime. This might create incentives for the police to reallocate their resources away from clearing these crimes, in favour of other policing activities.