Information about the impact of some factors aids short-term forecasts of caseload trends, and information about others is useful when deciding whether to modify court operations. Two distinct types of factors are considered. One set consists of background variables that represent the sources of appeals. A hypothesis tested, for example, is that more crime and more criminal filings in the trial courts may produce more criminal appeals. On the civil side, major background variables include trial court filings and real personal income. The number of judgeships in general jurisdiction trial courts is an important background variable for both criminal and civil appeals. Other factors explored are features of court structure and procedure that may attract or deter appellate filings. The importance of these variables is based on the assumption that people balance costs and benefits when deciding on a course of action. The factors are analyzed using a standard econometric regression analysis that differentiates the impacts of the variables and measures effects unique to individual States. 10 tables and 21 footnotes.