We explore the relationship between Shephard's input distance function and Luenberger's benefit function. We point out that the latter can be recognized in a production context as a directional input distance function which can exhaustively characterize production technologies under appropriate assumptions on input disposability. McFadden's composition rules for input sets and input distance functions are then extended to the directional input distance function. Working Paper 95-09 Scientific Article No. , Contribution No. from the Maryland Agricultural Experiment Station.

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We study the wavefronts (i.e. the surfaces of constant phase) of the wave discussed by Aharonov and Bohm, representing a beam of particles with charge q scattered by an impenetrable cylinder of radius R containing magnetic flux @. Defining the quantum flux parameter by a = q@/h, we show that for the case

Agricultural research has fostered productivity growth, but the historical influence of anthropogenic climate change on that growth has not been quantified. We develop a robust econometric model of weather effects on global agricultural total factor productivity (TFP) and combine this model with counterfactual climate scenarios to evaluate impacts of past climate trends on TFP. Our baseline model indicates that anthropogenic climate change has reduced global agricultural TFP by about 21% since 1961, a slowdown that is equivalent to losing the last 9 years of productivity growth. The effect is substantially more severe (a reduction of ~30-33%) in warmer regions such as Africa and Latin America and the Caribbean. We also find that global agriculture has grown more vulnerable to ongoing climate change.

SUMMARY: This paper explores how professionals ' universal, reductionist

This paper introduces a new technique for measuring productivity growth and applies it to a sample of APEC countries. The technique is based on a version of Luenberger's shortage function which generalizes Shephard's input and output distance functions.

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