Book contents
- Frontmatter
- Dedication
- Contents
- Acknowledgements
- 1 Representation Inside and Outside Congress
- 2 Representation and Evaluation on the Senator's Terms
- 3 Measuring Presentational Styles with Senate Press Releases
- 4 Measuring Presentational Styles in Thousands of Press Releases
- 5 The Types of Presentational Styles in the U.S. Senate
- 6 The Electoral Connection's Effect on Senators' Presentational Styles
- 7 The Correspondence between Senators' Work in Washington and Presentational Styles
- 8 Why Presentational Styles Matter for Dyadic Representation
- 9 Why Presentational Styles Matter for Collective Representation
- 10 Presentational Styles and Representation
- Methods Appendix
- Bibliography
- Index
Methods Appendix
Published online by Cambridge University Press: 18 December 2013
- Frontmatter
- Dedication
- Contents
- Acknowledgements
- 1 Representation Inside and Outside Congress
- 2 Representation and Evaluation on the Senator's Terms
- 3 Measuring Presentational Styles with Senate Press Releases
- 4 Measuring Presentational Styles in Thousands of Press Releases
- 5 The Types of Presentational Styles in the U.S. Senate
- 6 The Electoral Connection's Effect on Senators' Presentational Styles
- 7 The Correspondence between Senators' Work in Washington and Presentational Styles
- 8 Why Presentational Styles Matter for Dyadic Representation
- 9 Why Presentational Styles Matter for Collective Representation
- 10 Presentational Styles and Representation
- Methods Appendix
- Bibliography
- Index
Summary
This appendix provides methodological details for the statistical model introduced in Chapter 4. It also details the data-generation process for latent Dirichlet allocation (Blei et al. 2003) used in Chapter 2 to examine the articles that cite Fenno (1978).
STATISTICAL MODEL AND ESTIMATION
Suppose that each senator i during each year in which he or she is in Congress t (t = 2005, 2006, 2007) can allocate attention to K (k = 1, …, K) issues in his or her press releases. Represent the attention senator i allocates to issue k during legislative session t as πitk· πitk is the expected proportion of press releases from senator i that is about the kth issue. Collect the attention a senator allocates to all K issues during a session into the vector πit = (πit1, …, πit K).
The attention a senator allocates to the issues probabilistically determines the topic of each press release. Suppose that each press release j (j = 1,…, Dit)from senator i in the tth session has only one topic, which I represent with τitj:if τitjk = 1, then the press release is about the kth topic, and the other K – 1elements of τitj are equal to zero. It follows that τitj is a draw from a multinomial distribution:
τijtπit ∼ multinomial(1, πit)
Given the topic of each press release, I draw its content. As a result of the preprocessing steps, I represent the jth press release from senator i in the tth legislative session as a count vector yijt, where typical element yijtz counts the number of times the zth word appears in press release yijt.
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- Information
- Representational Style in CongressWhat Legislators Say and Why It Matters, pp. 171 - 182Publisher: Cambridge University PressPrint publication year: 2013