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Presidential Approval: the case of George W. Bush

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Abstract

Abstract We use a Bayesian dynamic linear model to track approval for George W. Bush over time. Our analysis deals with several issues that have been usually addressed separately in the extant literature. First, our analysis uses polling data collected at a higher frequency than is typical, using over 1,100 published national polls, and data on macro-economic conditions collected at the weekly level. By combining this much poll information, we are much better poised to examine the public’s reactions to events over shorter time scales than can the typical analysis of approval that utilizes monthly or quarterly approval. Second, our statistical modeling explicitly deals with the sampling error of these polls, as well as the possibility of bias in the polls due to house eects.,Indeed, quite aside from the question of “what drives approval?”, there is considerable interest in the extent to which polling organizations systematically diverge from one another in assessing approval for the president. These bias parameters are not only necessary parts of any realistic model of approval that utilizes data from multiple polling organizations, but easily estimated via the Bayesian dynamic linear model. The determinants of presidential approval is one of the chestnut problems in the study of American politics. For political methodologists it is also one of the chestnut quantitative issues, and clearly the leading example for our study of time series methods, dating back at least to Hibbs (1973). While the earliest studies were for the US, the industry has branched out to most democ- racies where a polling industry provides repeated measures of approval. If we take the subfield as starting with Mueller’s (1973) work, the original question related to the impact do exoge- nous events (war for Mueller) on presidential approval. While the impact of events has been of some continued interest (particularly in the work of MacKuen 1983), most work has been on the more general determinants of approval, and particularly the economic determinants of approval. Methodologically, most analyses have used Gallup polls to measure approval, with almost all analysts treating the more or less monthly polls as monthly data. With very few exceptions analysts have ignored measurement error in this monthly data. Also, with few exceptions, analysts have not combined information from dierent,polling houses, nor have they treated the unit of analysis as anything other than the month. This makes sense in the context of

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  • Kathleen A Frankovic
McDermott, Monika and Kathleen A. Frankovic. 2003. "Horserace Polling and Survey Method Effects: an analysis of the 2000 campaign." Public Opinion Quarterly 67:244-264.