Before future library needs can be estimated, economic and demographic variables that influence the demand for library services must be projected and estimating equations relating library needs to economic and demographic parameters developed. This study considers the size, location and age-sex characteristics of Indiana's current population and projects these population characteristics through 1990. A partial profile of the Indiana economy, including educational attainment and employment data, is also presented. Projections of the demand for future library resources are essential to efficient, intelligent planning for library facilities and, if the state of Indiana is to supply its future citizens with adequate library services, both careful planning and improved organization will be required. (Author/NH)