ABSTRACT
This chapter outlines the general requirements of their effective measurement before examining in some detail the issue of estimating local multipliers, as these are relevant for the measurement of economic growth impacts. In the case of urban renewal or transportation projects, labour and capital income earned in the activity constitutes the measure of direct benefit; in the case of increased tourist spending resulting from a recreation or other project. There are three types of local multipliers which have played a prominent role in urban and regional impact analysis: economic base multipliers, Keynesian multipliers and input–output multipliers. The simplest type of multiplier derives its origins from the export or economic base theory of growth, the theory which explains development and decline in terms of the performance of an area's export or economic base. The economic base comprises the sectors of economic activity. The economic base multiplier is defined as the ratio of total economic activity to basic activity.
