SUMMARY We present a newly developed approach of combining controlled‐source seismology (CSS) and local earthquake tomography (LET) data to obtain a new 3‐D crustal model of the western Alpine region. Our approach combines either data by taking into account the strengths of the individual seismic methods. Our western Alpine 3‐D model is primarily based on a well‐defined Moho, constrained by CSS and LET data, and includes smooth lateral variations in seismic velocities mainly constrained by LET data, but locally also by CSS data. The consistent combination of results from the two different seismic methods is feasible due to LET Moho elements, as defined by characteristic P‐wave velocities and their uncertainty estimates. These uncertainty estimates are based on values of the diagonal element of the resolution matrix, absolute P‐wave velocities that are typical for crust and mantle and a specific velocity gradient across the Moho discontinuity. Finally, our definition of LET Moho elements and their uncertainties is validated by comparisons of highest quality Moho results from both methods coinciding in 353 localities. Our model clearly shows three Moho surfaces, being Europe, Adria and Liguria as well as major tectonic structures like suture zones and the high‐velocity Ivrea body. In general, it is in a good agreement with previous studies. The biggest differences occur along plate boundaries, where the strong lateral velocity variations are best resolved by LET. Due to the larger number of available Moho reflector elements a more accurate definition of plate boundaries at Moho level is possible and, therefore, new insights in deep lithosphere structures of the Alpine collision zone can be expected. Furthermore, our new 3‐D crustal model directly includes a 3‐D migrated image of the Ivrea body.

This article reviews methodological issues confronting authors and users of cconomic impact studies of public colleges and universities. Questions addressed includc the following: How should economic impact of regional public collegcs and univcrsities be defined? What considerations should govern thc definition or the geographical study area? How should tax support of publicly supported institutions be addressed? The article includes perspectives from recent literature considering these questions from both short-term and long-term perspcctives. Resolution of these issues depends upon careful delineation and cornmunication of thc alternative states of world between which the hypothetical impact is measured. CONOMIC IMPACT STUDIES CONTINUE TO BE AN IMPORTANT PUBLIC RELA-E tions tool for state colleges and universities (Dean 1991), especially in Limes of budgctary shortfalls and rescissions. Yet, such studies arc frequenlly criticized as biased in approach and conclusions. Some critics decry past studies as publicizing only the positive (Knapp et al. 1990). Others point out that such studics too frcqucnlly employ definitions which inflatc the impacts (Elliott et al. 1987; Bluestone 1993). Still others argue that past methodology has ignored univcrsitics' contributions to the stock of human capital and regional economic dcvclopmcnt (c.g., Berger and Black 1993; Bluestone 1993). A recent article in this journal (Hcdrick ct al. 1990) examined (and refuted) oftcn heard contentions that ncgativc regional effects of auxiliary activities of higher education institutions outweigh psitivc effects associated with their spending. Roger Beck is an associate professor of agribusiness economics at Southern Illinois University at Carbondale; Donald Elliott and John Meisel are professors of economics at Southern Illinois University ai Edwardsville; and MichaelWagner is an independent research consultant. The authors wish to thank anonymous referees ,for their comments and suggestions on earlier versions of this paper. Any remuining errors are the responsibiliiies of the authors.

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