The Southern Illinois Poll is an empirical study of the opinions of the people who live in the region of southern Illinois. The study is primarily based on surveys conducted for the Paul Simon Public Policy Institute These surveys are based on a sample of telephone subscribers living in the 18 southernmost counties in Illinois, all south of Interstate 64. The respondents are located through random digit dialing techniques, which included both land lines and cell phones in the sample frame. The survey was contracted to Customer Research International of San Marcos, Texas, which did the sampling and the interviews following specifications provided by the staff of the Simon Institute.
The most recent survey is also supplemented by the first annual southern Illinois survey, commissioned by the Paul Simon Public Policy Institute in the spring of 2010. This was also a telephone survey and it was in the field from April 5 - 13 of 2010. A sample was taken of 401 registered voters and it, too, had a margin of error of 4.9 percent at the 95% confidence level. That poll was also conducted by Customer Research International under the auspices of the PSPPI . While we think the two most recent polls are compatible and both capture reliable pictures of public opinion in southern Illinois, there are some important methodological differences. The 2010 poll depended on a sampling frame of registered voters who were then located and called on land lines. The 2011 sampling frame consisted of random digit dialing of telephone numbers which included both land lines and cell phones. Thus, the most recent survey is likely to have cast a somewhat wider net and included more mobile and perhaps younger populations than did the 2010 survey did.
The current surveys provide some very interesting and useful data documenting what the people of this vital region think and especially how they regard their political leaders, the services provided by their governments, and their positions on a wide variety of contemporary political and social issues. This is one important objective for this study. However, the 2011 study was also specifically designed to be a partial replication of two earlier studies done in 1976 and 1977. These two studies were similar in design and content and provide an extremely interesting opportunity for longitudinal comparisons in the same region across a thirty-five year time span.