migratory waterfowl habitat) of prairie potholes. No brief resume can convey 

 the care with which the author handles the complex web of details underlying each 

 of these issues. However, two examples must be cited; namely, the excellent 

 discussion of wetland typology and the profitability of wetland drainage, and 

 the documentation of the fact that prairie potholes are more productive than the 

 lacustrine wetlands and myriad lakes of central and north-central Canada in the 

 production of migratory waterfowl. 



For certain types of prairie potholes, drainage is unprofitable at the 

 prevailing (1971) farm support price and drainage subsidization levels. Drainage 

 of small seasonal (class 1 and 2) potholes in southern Minnesota tends to be 

 quite profitable and would remain profitable in the absence of all government 

 agricultural support payments. The drainage of large, permanent marshes in 

 northwestern Minnesota is not always profitable even with strong Federal price 

 support, crop disaster insurance, and low interest loan programs. 



Waterfowl can breed in the vast region that lies directly to the north of 

 the prairie pothole region. Documentation of the net marginal productivity of 

 prairie potholes in the production of migratory waterfowl involves complicated 

 research resting on numerous disciplines. The U.S. Fish and Wildlife Service 

 gathered much of the bird count data, performed certain field experiments 

 documenting the recruitment class versus number of wetlands relation, and did 

 much of the statistical modeling Goldstein uses to demonstrate the validity of 

 the hypothesis that prairie pothole wetlands produce waterfowl. 



5. Brown, G.M., Jr., and J. Hammack. 1972. Dynamic economic management of 

 migratory waterfowl. The Review of Economics and Statistics 15(l):73-80. 



This justly famous article, the forerunner to the book by the same authors 

 (see [10]), treats prairie pothole wetlands as a factor input for a productive 

 process in which the output is migratory waterfowl. Adult breeding waterfowl 

 are the other factor input in the estimated aggregate production function. The 

 benefits provided by the duck population stem from the consumption of ducks by 

 hunters. The instantaneous gross aggregate benefits conferred is a function of 

 the number of ducks bagged, the hunters' income, and various taste variables. 

 Net benefits are gross benefits minus a social cost term, where social costs are 

 an increasing convex function of the number of nesting ponds in south-central 

 Canada. 



The authors find that at 1974 easement payment levels for Canadian prairie 

 potholes (about $5 per annum per pond), the socially optimal amount of Canadian 

 prairie pothole acreage is about 20 times the historical average. At somewhat 

 higher easement costs ($12-$17), the model calculates the socially optimal number 

 of Canadian breeding ponds to be 5 times the historical average. 



6. Gupta, T.R. 1973. Economic criteria for decisions on preservation and 

 alteration of natural resources with special reference to freshwater 

 wetlands in Massachusetts. Ph.D. Thesis. University of Massachusetts, 

 Amherst. 271 pp. 



Gupta studies the impact of recent Massachusetts legislation designed to 

 limit drainage and filling of wetlands. He describes the institutional forces 



15 



