Illegal wells are frequent in some of the large agricultural groundwater-using regions, thus preventing other groundw'ater measures to be effective in reducing pressure on an aquifer (see Chapter 4 for details). Development and the Environment: The Implications of Agricultural Electricity Subsidies in India", The Journal of Environment & Development, Vol. Frontiers in water resource economics, Springer, New York. Water Markets for the 21s' Century: What Have We Learned?,