Canada: How Many Glaciations?

Editor's note: The first President's Symposium was held during the cag annual meeting at the University of Winnipeg in 1983. The idea was to air some broad and invigorating topic to which invited specialists from across the country could contribute under presidential direction. The inaugural topic selected by the president, Professor D.C. Ford, was ‘Canada: how many glaciations?’ The specialist contributors certainly learned a great deal, and the symposium was well received by the general membership whom the specialists wished to interest. This article consists of a summary of the presentations made by the various contributors and a concluding polemic.     

ALLOCATIVE EFFICIENCY OF RURAL NEVADA WATER SYSTEMS: A HEDONIC SHADOW COST FUNCTION APPROACH*

ABSTRACT. The efficiency of the water utility firms in rural Nevada and their input optimization are examined in this study. The empirical methodology incorporates a hedonic specification of the nonminimum globally concave cost function in estimating the effect of the regulatory environment and the quality of water services on the optimum utilization of inputs. Allocative distortions are introduced through shadow prices and are specified as functions of regressors which make distortion factors firmand input-specific. The results show that 76 percent of the water utilities of rural Nevada in the sample overutilize energy relative to labor. The impact of allocative distortions on each firm's cost is also computed.     

Prehistoric Human Impacts to Marine Mollusks and Intertidal Ecosystems in the Pacific Islands

From long-term stratigraphic records in Pacific Island archaeological sites, researchers have documented alterations to molluskan species richness and abundance, decreases or increases in mollusk shell size and, in rare cases, human foraging may have contributed to the extirpation of mollusk taxa. Mollusks perform critical ecosystem functions in tropical intertidal environments, including improving water quality through filtration, regulating algal cover, and increasing habitat and substratum complexity through ecosystem engineering. These critical ecosystem functions can be negatively affected by human foraging, possibly contributing to decreased resilience of coral reefs to climatic alterations. We review modern ecological research on human impacts to mollusks and intertidal ecosystems that illustrates the mechanisms and effects of human foraging. We then examine centuries to millennial scale archaeological records from the Pacific Islands to understand long-term, time-averaged trends in human impacts to intertidal ecosystems.