T HIS article is based on a milk supply adjustment study. A primary objective was to test the use of linear programming techniques on the problems of farmers: how useful it would be for telling farmers what production adjustments would pay in response to changes in technical and economic conditions. The empirical results illustrate particular extensions in the application of programming techniques, but, more important, the results are of interest from two viewpoints: first, they indicate profitable lines of change in production when facing a range of changes in conditions of factor supply, prices of labor, prices of milk, and technical possibilities. Second, they offer reasonable explanations of changes taking place in important sectors in the southern states. The data were drawn largely from dairy farms in the Piedmont areas of North Carolina, but the empirical results should also apply in general to the much larger Piedmont region of the South and, to a somewhat lesser extent, to the larger areas in which cotton and tobacco are major crops. Production of milk for fluid use increased rapidly on these farms in the North Carolina Piedmont areas between I949 and I954. Expansion of dairying was accompanied by certain changes: enlargement of smaller farms by the renting of additional land, an increase in production of pasture and hay, shifts from lower-producing breeds to the Holstein breed, elimination of cotton or tobacco on many of the dairy farms, reduction in labor supply, and an increase in use of tractors. Assumptions

THE basic question to which this paper is addressed is "What is the importance of distance in determining the pattern of Western European trade?"The importance of distance in the pattern of trade has, of course, always been recognized.The assumption of "no transport costs," which has always been necessary in expositions of theories of international trade, is a recognition of the fact that transport costs, that is, the costs of covering distance, exist and are significant; so that abstraction from them has to be made quite explicitly in order to analyze other elements such as factor endowments.' 0 0 t 0 0 0 "inCq 0 e oo HO ~, "d0 80 8 00 0 * .. 99"o 'A-.

A presidential vote function and a presidential approval ratings function are jointly estimated for U.S. post-war observations. The estimation technique treats the two equations as seemingly unrelated regressions with unequal numbers of observations. Cross-equation restrictions implying that voters and poll respondents use identical standards in judging the economic performance of incumbents are imposed and tested. Estimates show that both votes and approval ratings are influenced by GNP growth and inflation. The results suggest that poll respondents are more inflation averse than voters; however, tests of this hypothesis are not conclusive.

Abstrac-t-The profits of leading firms in concentrated markets may be due to market share related cost efficiencies or market power. One way to identify the separate effect of market power is to analyze the relationship of market concentration and market share to the prices charged by firms in local geographic markets. This study analyzes the prices charged by supermarkets in local Vermont markets. Prices are significantly higher in more concentrated markets. The Herfindahl index, as a concentration measure, out-performs the four-firm or one-firm concentration ratio. Herfindahl marginally out-performs a firm's market share as a predictor of its price level.