Media Slant: Slant Contagion and Polarization

Table of Links

Abstract and 1 Introduction 2. Data

3. Measuring Media Slant and 3.1. Text pre-processing and featurization

3.2. Classifying transcripts by TV source

3.3. Text similarity between newspapers and TV stations and 3.4. Topic model

4. Econometric Framework

4.1. Instrumental variables specification

4.2. Instrument first stage and validity

5. Results

5.1. Main results

5.2. Robustness checks

6. Mechanisms and Heterogeneity

6.1. Local vs. national or international news content

6.2. Cable news media slant polarizes local newspapers

7. Conclusion and References

\ Online Appendices

A. Data Appendix

A.1. Newspaper articles

A.2. Alternative county matching of newspapers and A.3. Filtering of the article snippets

A.4. Included prime-time TV shows and A.5. Summary statistics

B. Methods Appendix, B.1. Text pre-processing and B.2. Bigrams most predictive for FNC or CNN/MSNBC

B.3. Human validation of NLP model

B.4. Distribution of Fox News similarity in newspapers and B.5. Example articles by Fox News similarity

B.6. Topics from the newspaper-based LDA model

C. Results Appendix

C.1. First stage results and C.2. Instrument exogeneity

C.3. Placebo: Content similarity in 1995/96

C.4. OLS results

C.5. Reduced form results

C.6. Sub-samples: Newspaper headquarters and other counties and C.7. Robustness: Alternative county matching

C.8. Robustness: Historical circulation weights and C.9. Robustness: Relative circulation weights

C.10. Robustness: Absolute and relative FNC viewership and C.11. Robustness: Dropping observations and clustering

C.12. Mechanisms: Language features and topics

C.13. Mechanisms: Descriptive Evidence on Demand Side

C.14. Mechanisms: Slant contagion and polarization

C.14. Mechanisms: Slant contagion and polarization

Here, we replicate Table 4, but instead of pre-FNC/MSNBC era newspaper endorsements, we distinguish observations by the county-level Republican vote share terciles (lowest tercile in the first column, second tercile in middle, and highest tercile in the last column). Qualitatively, we find the same pattern: The relative FNC exposure coefficient is negative in the first column, positive plus relatively small in the second column (coefficients in columns 1 and 2 are not significant), before turning significant, positive, and large in the last column.

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:::info This paper is available on arxiv under CC 4.0 license.

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:::info Authors:

(1) Philine Widmer, ETH Zürich and [email protected];

(2) Sergio Galletta, ETH Zürich and [email protected];

(3) Elliott Ash, ETH Zürich and [email protected].

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