Economists and regional scientists generally agree that the inter-industry or input-output model provides the most effective means to describe and analyze a region's economy. The input-output technique is unique in that it simultaneously accounts for all components of the regional economy so that growth in each sector is consistent with that in all other sectors. Construction of an I-O model is a practical investment since it can be applied to the analysis of almost every facet of the regional economy and thus a new model need not be developed each time a new phenomenon is to be studied. This exposition begins with a discussion of both the economic base model and the I-O technique and also contains a discussion of the advantages of the I-O method over the economic base model. The discussion concludes with a justification for the use of primary survey based data rather than secondary information sources in constructing the model.