A Method to Optimize Gross Fixed Capital Investments for Water Conservancy in China

A major concern of policymakers and researchers in China is finding an appropriate size of the gross fixed capital investments for water conservancy (GFCIWC). This paper determines the optimal proportion of GFCIWC to GDP. Unlike engineering economics, we investigate the benefits of GFCIWC at a macro-economic level, using the 1999 input-output table extended for water conservancy. Different kinds of impacts are induced by GFCIWC. These include forward benefits (flood control, water supply, irrigation, hydroelectric power, soil and water conservation, environmental protection) and backward benefits for GDP; negative social effects; and opportunity costs of GFCIWC. The results are put into a set of regression equations between total benefits of GFCIWC and the proportion of GFCIWC to GDP, from which the optimal proportion - or a desirable range - can be determined. The results may provide policymakers with guidelines for allocating investments.