Methodology and findings are reported for a series of statistical analyses conducted to identify those factors that account for variations in instructional unit costs (IUC) among the Illinois community colleges. The first analysis described in the report correlates five measures of district wealth with total IUC (i.e., total instructional costs divided by total credit hours produced) and two measures of variable unit costs (i.e., the portion of the IUC that fluctuates with enrollment). The five measures of district wealth included in the analysis are: property wealth per capita; property wealth and tax rate per capita; property wealth per full-time equivalent (FTE) enrollment; property wealth and tax rate per FTE enrollment; and per capita income. The second analysis examines the correlation of total and variable unit costs with 15 non-wealth factors, including: tuition and fees, faculty load, full-/part-time faculty ratio, and college program mix (i.e., the percentage of instructional effort devoted to each of seven curricular areas). The report then describes the application of two stepwise regression analysis procedures to determine the relation between the combined impact of 3 wealth and 15 non-wealth factors and IUC. The final analysis examines the correlation between measures of wealth and IUC adjusted to exclude equalization funding and tuition and fees. The report concludes with a discussion of the implications of the study for state funding. (JP)