a joint product analysis of the adoption of modern cereal varieties in developing countries semi dwarf wheat varieties have been slow to diffuse in some regions despite their superior grain yield we analyze varietal differences in yields of the joint products of grain and straw the decision to adopt new varieties and nitrogen demand the low straw yield of semi dwarf varieties under low input conditions is shown to be a plausible explanation for their slow adoption in some regions first generation modern varieties induced a large increase in the derived demand for nitrogen but subsequent varietal development appears to have had little impact on nitrogen demand

nonseparable preferences frisch labor supply and the consumption multiplier of government spending one solution to a fiscal policy puzzle this paper proposes a theoretical explanation of the positive consumption multipliers of government spending often found in the data the explanation requires two ingredients first labor demand expands e g prices are sticky second general nonseparable preferences over consumption and leisure should be such that the two goods are substitutes that is frisch labor supply elasticity is lower than the constant consumption elasticity this implies that constant consumption labor supply shifts left existing empirical evidence on the relative magnitudes of the two elasticities supports this hypothesis the parametric conditions under which the result occurs are consistent with restrictions of concavity and noninferiority of consumption and leisure

poverty productivity and production environment a review of the evidence abstract this paper reviews the state of knowledge about the key issues needing to be understood to satisfactorily resolve a long standing debate within the consultative group for international agricultural research cgiar system the debate revolves around the effects on various populations particularly the poor of different allocations of research effort between marginal and favoured production environments this paper specifically focuses on what is known about the geographical distribution of the rural poor across agro ecological zones and over time variations in the income generating activities including non agricultural activities engaged in by the poor are examined and the ways in which specific technology packages affect the economic well being of different types of households both directly and indirectly

sustaining growth in agriculture a quantitative review of agricultural research investments abstract growth in agriculture depends on many things but one of the most important is investment in agricultural research decision making in the agricultural research policy area can only be aided by access to better information this article overviews a recent endeavor to move policy dialogue beyond merely qualitative impressions towards a process that is underpinned with new and cogent data the data used have been assembled at isnar in a manner designed to make comparisons both over time and between countries more valid than has been the case in the past the comparisons thus possible reveal considerable diversity both between countries and between broad regional aggregations also illuminated here are issues related to the commodity orientation capital and labor intensity and size and scope of particular national programs

market efficiency in agricultural futures markets market efficiency and unbiasedness are tested in four agricultural commodity futures markets live cattle hogs corn and soybean meal using cointegration and error correction models with gqarch in mean processes results indicate each market is unbiased in the long run although cattle hogs and corn futures markets exhibit short run inefficiencies and pricing biases models for cattle and corn outperform futures prices in out of sample forecasting results also suggest short run time varying risk premiums in cattle and hog futures markets

can consumption spillovers be a source of equilibrium indeterminacy in the framework of a one sector exogenous growth model we show that consumption externalities are not a source of equilibrium indeterminacy when the labor supply is inelastic whereas they are under endogenous labor supply in particular when the marginal rate of substitution between own consumption and the others consumption is constant along the equilibrium path the equilibrium may exhibit indeterminacy when the following two conditions are simultaneously satisfied i both consumption and production externalities are present and ii the elasticity of the labor demand is larger than the elasticity of the frisch labor supply in contrast when the marginal rate of substitution is not constant the equilibrium may exhibit indeterminacy even if the previous two conditions are not met in this case the equilibrium can exhibit indeterminacy even if production externalities are absent we also show that these results do not apply to an endogenous growth model where indeterminacy may arise only when condition ii is met

new markets and technological change for the traditional cereals in semiarid sub saharan africa the malian case during the last three decades in sub saharan africa development and research resources have concentrated on the higher rainfall and irrigated regions especially on export crops and the principal food crops grown there there has been much less concern and investment in semiarid regions without irrigation another negative factor has been the lack of public policy concern with the profitability of the basic food crops with good weather prices collapse with bad weather governments and ngos dispense food crops as food aid or at subsidized prices this article documents the importance of the demand side to facilitate diffusion of new technologies for the basic food commodities of semiarid regions the traditional cereals with farm programming models aggregated into a sector model the combination of technological change and demand shifts for sorghum are evaluated in one semiarid region where the traditional cereals are concentrated it focuses on combining policies to increase the prices farmers receive after introduction of technologies that use higher input levels it also compares benefits of a strategy that focuses on yield and demand increases for a traditional cereal of the semiarid region sorghum with two alternative strategies for the higher rainfall zone

capital labor substitution and equilibrium indeterminacy empirical evidence indicates that the elasticity of capital labor substitution for the aggregate u s economy is below unity in contrast the existing indeterminacy literature has mostly restricted attention to a cobb douglas production function which imposes a substitution elasticity exactly equal to unity this paper examines the quantitative relationship between capital labor substitution and the conditions needed for equilibrium indeterminacy and belief driven fluctuations in a one sector growth model with variable capital utilization the substitution elasticity has little quantitative impact on the minimum degree of increasing returns needed for indeterminacy however when capital utilization is constant a below unity substitution elasticity sharply raises the minimum degree of increasing returns in this version of the model lower substitution elasticities impose a higher adjustment cost on labor hours that cannot be mitigated by shifts in the capital utilization rate overall our results show that empirically plausible departures from the cobb douglas specification can make indeterminacy more difficult to achieve

modern varieties productivity and sustainability recent experience and emerging challenges abstract the contribution of modern varieties of cereal crops to increased productivity in the postgreen revolution period is reviewed and the future role of hybrids and biotechnology discussed particular emphasis is given to the ways in which modern varieties may contribute to input efficiency and sustainability finally economic and institutional issues in restructuring plant breeding programs for the most efficient use of resources in both the public and private sectors and at the national and international levels are analyzed

on the minimum degree of returns to scale in sunspot models of the business cycle abstract bennett and farmer j econ theory 93 2000 118 claim that the degree of increasing returns to scale required for indeterminacy in a single sector growth model can be lowered by allowing for preferences that are non separable in consumption and leisure in this paper i show that the example they give violates concavity in a more general setup which does not impose specific functional forms on utility i prove that there are no concave utility functions compatible with indeterminacy if the elasticity of scale is lower than the inverse of the labor share in production

expectational stability of sunspot equilibria in non convex economies we examine the stability under learning e stability of sunspot equilibria in non convex real business cycle models the production technology is cobbdouglas with externalities generated by factor inputs we establish that with a general utility function the well known benhabib farmer condition benhabib and farmer 1994 that the labor demand curve is upward sloping and steeper than the frisch labor supply curve is necessary for joint indeterminacy and e stability then with a separable utility function and allowing for negative externalities from capital inputs we discover large regions in parameter space corresponding to stable indeterminacy that is learnable sunspot equilibria these existence results overturn the conventional wisdom that sunspot equilibria in rbc type models are inherently unstable and provide concise closure to the stability puzzle of evans and mcgough 2005b

nonseparable preferences fiscal policy puzzles and inferior goods nonseparable preferences over consumption and leisure can generate an increase in private consumption in response to government spending as found in the data in a frictionless business cycle model however the conditions on preferences required for these result to obtain hold if and only if the consumption good is inferior similarly positive co movement of consumption and hours worked occurs if and only if either consumption or leisure is inferior

indeterminacy and increasing returns abstract we investigate properties of the one sector growth model with increasing returns under two organizational structures capable of reconciling the existence of aggregate increasing returns with competitive behavior by firms the first involves input externalities the second involves monopolistic competition we show for parameters in close accord with recent literature on real business cycles that the model displays an indeterminate steady state that can be exploited to generate a model of business fluctuations driven by self fulfilling beliefs in our first class of models growth is generated by exogenous increases in factor productivity in the second class the marginal product of capital is large enough for endogenous growth journal of economic literature classification numbers e00 e3 o40

the price forecasting performance of futures markets for live cattle and hogs a disaggregated analysis four hypotheses about the price forecasting performance of live cattle and hog futures are tested using disaggregated data live cattle futures are found to have inadequate forecasting performance for each hypothesis and do not provide better forecasts than lagged cash prices live hog futures perform well for three hypotheses but not when economic conditions are unstable hog futures provide better forecasts than lagged cash prices the analysis does not support the contention that these futures markets are agencies for rational price formation

market efficiency and cointegration an application to the sterling and deutschemark exchange markets abstract the assumption that the foreign exchange market is efficient that is that agents are risk neutral and use all available information rationally so that the forward exchange rate is an unbiased predictor of the future spot rate is a property often imposed in theoretical international macroeconomic models although a vast empirical literature has evolved to test market efficiency we use recent developments in the theory of cointegration to provide new methods of testing several aspects of foreign exchange market efficiency we ffind evidence inconsistent with market efficiency for both germany and the united kingdom

returns to investment in less favored areas in developing countries a synthesis of evidence and implications for africa abstract a large proportion of world s population lives in marginal or less favored areas these areas are of home to the poorest segment of the population particularly in rural areas in the past government has targeted their resources mostly to the high potential or irrigated areas these investments have generated rapid growth in agricultural production for example the so called green revolution in south and southeast asia in the 1970s and 1980s which in turn has helped to alleviate rural and urban poverty however as investments continue to increase in these favored areas their marginal returns have begun to decline and environmental problems are emerging evidence shows that it is in the marginal areas or less favored areas where many investments may have higher returns today these investments may have even larger impacts on poverty reduction and environmental protection as poor people are increasingly concentrated in the marginal areas where natural resources have already been severely degraded this study synthesizes some recent studies from india and china on the relative returns to investments in favored and less favored areas and presents some preliminary evidence from uganda and offers some policy implications for africa on how governments and international donors can reprioritize their investment portfolio in order to achieve multiple goals of growth poverty reduction and environmental protection

local determinacy with non separable utility this paper introduces general formulations for both technology with input substitution and non separable utility compatible with balanced growth and stationary worked hours into a benchmark rbc model it is shown that intertemporal substitution and input substitutability lead to local determinacy and rule out stationary sunspot equilibria when labor demand is downward sloping in contrast with recent results obtained under the assumption of separable utility the main intuition behind this result is shown to work as follows in contrast with separable preferences increasing the elasticity of intertemporal substitution in consumption necessarily implies decreasing the elasticity of constant consumption labor supply when utility is non separable and concave which affects unfavorably the occurrence of local indeterminacy

research for marginal environments are we underinvested abstract evidence is presented to show that adoption of modern wheat varieties in rainfed marginal environments of the developing world has lagged substantially compared to adoption in favoured well watered areas possible reasons for this lag are discussed and a simple congruency model is used to examine the case for shifting research resources from favoured to marginal environments with particular reference to wheat breeding application of the model to resource allocation in wheat research at the international level and for india a major wheat producing country suggests that the proportion of research resources invested in marginal environments has been adequate or even a bit high relative to the share of the value of wheat produced in these environments taking into account both efficiency and equity criteria

linking technical change to research effort an examination of aggregation and spillovers effects we used a disaggregate approach to examine investment efficiency of wheat breeding research in india india s total research effort comprizes 20 research programs spread across 50 experiment stations a technology spillover matrix was constructed for both potential and actual spillovers spillovers and free riding were dominant characteristics of technical change during the period studied although the aggregate rate of return to wheat improvement research in india was estimated to be 55 eight programs were found to have earned a negative rate of return when spillins were taken into account research output is concentrated on a few strong programs the two strongest programs generated 75 of all the technical change benefits even though they claimed just 22 of research resources these two programs include a significant degree of overlap while on the other hand many farmers were not reached by any of the programs 56 and 78 of rainfed and durum area respectively in 1990 was still sown with pre 1976 varieties 2001 elsevier science b v all rights reserved

can environmental taxation stimulate growth the role of indeterminacy in endogenous growth models with environmental externalities abstract this paper examines the effects of environmental taxation on long run growth in an infinitely lived representative agent model of endogenous growth with negative pollution externalities the novelty of this paper lies in its investigation of how the long run effects of environmental taxes are affected by the possible emergence of indeterminacy of equilibria in romer s 1986 increasing returns and long run growth journal of political economy 94 1002 1037 learning by doing model with endogenous labor supply the analysis shows that environmental taxation generally enhances harms long run growth when the balanced growth path is indeterminate determinate

aggregate instability under balanced budget consumption taxes a re examination we re examine the destabilizing role of balanced budget fiscal policy rules based on consumption taxation using a one sector model with infinitely lived households we consider a specification of preferences derived from jaimovich 2008 14 and jaimovich and rebelo 2009 15 which is flexible enough to encompass varying degrees of income effect when the income effect is not too large we show that there exists a laffer curve which explains the multiplicity of steady states and that non linear consumption taxation may destabilize the economy promoting expectation driven fluctuations if the elasticity of intertemporal substitution in consumption is sufficiently larger than one and the tax rate is counter cyclical with respect to consumption numerical illustrations also show that consumption taxation may be a source of instability for most oecd countries for a wide range of structural parameters configurations we finally prove the robustness of our conclusions if we consider a discrete time setup

unemployment and indeterminacy abstract using an efficiency wage model we examine the relationship between indeterminacy and unemployment insurance it is shown that the less unemployment insurance is the more likely equilibrium is to be indeterminate equilibrium can be indeterminate even without externalities or increasing returns which makes a sharp contrast to the recent literature on indeterminacy our result is based on the fact that the no shirking condition with marginal utility of wealth kept constant is downward sloping when income insurance is not perfect

conditional variance and the risk premium in the foreign exchange market abstract we investigate the existence of a risk premium in the foreign exchange market based on the conditional variance of market forecast errors the forecast errors are assumed to follow the arch process introduced by engle 1982 estimation and diagnostic testing of the model are discussed and results are presented for the currencies of the united kingdom france germany japan and switzerland