Study Significance
If corporate ownership shifts local news away from local topics toward national politics and toward a partisan slant, this supply-side change can weaken accountability of local officials and contribute to mass political polarization.
Measuring Coverage, Slant, and Viewership
The authors used extensive data on local news programming and viewership to track the amount of coverage devoted to national versus local politics, an index of ideological slant in reporting, and audience metrics for those programs.
Comparison Strategy
The study compared news programs at stations that were acquired by a conglomerate owner to other news programs airing in the same media markets over the same period, using the latter as comparison cases.
Main Findings
Following acquisition, affected stations showed substantial increases in coverage of national politics at the expense of local politics, a significant rightward shift in ideological slant, and a small decrease in viewership compared with other programs in the same markets.
Interpretation of Results
These patterns point to a substantial supply-side role—changes in ownership and editorial decisions—in driving trends toward nationalization and increased ideological polarization of local political news.
