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Characteristics of communal club members who use input packages are studied using a survey of communal clubs serviced by Africa Co‐operative Action Trust (Acat) in KwaZulu during 1989. Discriminant analysis shows that full input package adopters tend to belong to older clubs, have less formal savings and receive more visits each year from KwaZulu Department of Agriculture (KDA) extension officers. They also have a greater proportion of land under sugar‐cane, larger farm sizes and a higher rand monetary value of livestock.

Members of older clubs benefit from greater club experience in ordering inputs and liquidity for securing discounts on bulk orders. Clubs also enable scarce KDA extension manpower resources to be used more effectively by focusing extension efforts on groups rather than individual farmers. Sugar‐cane production probably indicates member willingness to innovate and the availability of funds to buy complete input packages for other crops. Increased access to land promotes input package adoption which can raise agricultural productivity. Development of institutional arrangements for a land rental market in KwaZulu should be considered. Higher monetary values of livestock reflect Increased ability to bear risk associated with technology adoption and that adopters have the means to purchase input packages  相似文献   

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Summary Jan Tinbergen originated the theory of policy in the 1950s. Here I apply it to contemporary macroeconomics. The two standard instruments of short-run demand management cannot achieve the two usual targets, full employment and price stability. With respect to those goals, these two instruments are collinear, except for small and transient effects on foreign exchange rates. But the mix of fiscal and monetary policies, relative to one another, does have important effects on the composition of national output, as between investment and consumption.I point out that policy-makers, like portfolio managers, should diversify the instruments they use when they are uncertain of their effects. I discuss some pitfalls in the empirical estimation of policy effects, especially possible misinterpretations of simple correlations, and I note that policy rules cannot be invariant to changes in macroeconomic structure. I argue that policy rules should involve responses to new information and in practice allow discretion. Finally, I suggest that Tinbergen's theory of policy needs to be extended to policy coordination among nations.Third Tinbergen Lecture delivered on October 20, 1989, in Utrecht for the Royal Netherlands Economic Association.  相似文献   
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Discriminating Among Alternative Theories of the Multinational Enterprise   总被引:6,自引:0,他引:6  
Recent theoretical developments have incorporated endogenous multinational firms into the general–equilibrium model of trade. One simple taxonomy separates the theory into "vertical" models, in which firms geographically separate activities by stages of production, and "horizontal" models, in which multiplant firms duplicate roughly the same activities in many countries. The authors nest a horizontal and a vertical model within a hybrid (unrestricted) "knowledge–capital model" and estimate the specifications with data on US foreign direct investment activity. In the nested econometric tests, the data sample cannot distinguish statistically between the unrestricted model and the restricted horizontal model, indicating that the latter captures virtually all of the determinants of FDI. The tests overwhelmingly reject the vertical model.  相似文献   
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"This paper describes the methodology used to incorporate AIDS mortality in recently revised World Bank population projections....The paper first reviews different approaches for projecting AIDS and its demographic consequences. This is followed by a summary of an epidemiological model that simulates the spread of HIV used in this analysis, and a demographic model that translates mortality from AIDS into population outcomes. These models are then used in a set of simulations, from which the effect of current HIV prevalence on projected future mortality is extracted. Finally, the extracted equations linking current HIV prevalence with future mortality indicators are applied to sub-Saharan countries with a measurable level of current HIV prevalence."  相似文献   
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