unequal vulnerability to climate change and the transmission of adverse effects through international trade in this paper we consider the unequal distribution of climate change damages in the world and we examine how the underlying costs can spread from a vulnerable to a non vulnerable country through international trade to focus on such indirect effects we treat this topic in a north south trade overlapping generations model in which the south is vulnerable to the damages entailed by global pollution while the north is not we show that the impact of climate change in the south can be a source of welfare loss for northern consumers in both the short and the long run in the long run an increase in the south s vulnerability can reduce the welfare in the north economy even in the case in which it improves its terms of trade in the short run the south s vulnerability can also represent a source of intergenerational inequity in the north therefore we emphasize the strong economic incentives for non vulnerable and a fortiori less vulnerable economies to reduce the climate change damages on more vulnerable countries

endogenous timing in games of commercial policy this paper analyzes various equilibria associated with intervention in trade in the context of noncooperative policy games with endogenous timing it is shown that while the subgame perfect equilibria in quota games always involve sequential play that is not necessarily the case in tariff games one implication of the analysis is that in contrast to existing theory trade is not eliminated in quota games another implication is that quotas are not necessarily inferior to tariffs the paper also examines the ways policy leaders and followers differ in their preferences over instruments and allows the choice over instruments to be determined endogenously this paper analyses various equilibria associated with intervention in trade in the context on non cooperative policy games with endogenous timing it is shown that while the subgame perfect equilibria in quota games always involve sequential play that is not necessarily the case in tariff games one implication of the analysis is that in contrast to existing theory trade is not eliminated in quota games another implication is that quotas are not necessarily inferior to tariffs the paper also examines the ways policy leaders and followers differ in their preferences over instruments and allows the choice over instruments to be determined endogenously

reap what you sow agricultural technology urbanization and structural change abstract this paper studies how productivity enhancing agricultural technology affects urbanization by provoking structural change we investigate these issues using a natural experiment in the united states the results show that technologies which improve crop productivity lead to a less urbanized economy as economic activity relocates from manufacturing and services towards agriculture the effects are highly persistent and are driven by the technology increasing agricultural labor demand our findings highlight the potentially unintended disruptive force of innovative technologies

voluntary export restraints and expectations an analysis of export quotas in oligopolistic markets the frequency of export quotas imposed as voluntary export restraints has been increasing this tends to create the expectation that similar export quotas will be imposed in the future even if free trade is allowed now the author analyzes the effect of such an expectation he demonstrates that if a quota is expected to be imposed on foreign exporting firms it intensifies the exporting firms competition in the prequota period this offsets the protection which the export quota as a voluntary export restraint will provide for domestic import competing firms in the future quota period copyright 1989 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

market equilibrium under the threat of a ver abstract this paper characterizes market equilibrium under oligopoly when a ver has introduced both asymmetry amongst exporters and uncertainty a restrained and an unrestrained exporter choose price strategically under the threat of a ver on the latter a pure strategy equilibrium is shown to result only when the probability of the ver is high otherwise a unique mixed strategy equilibrium results as the probability of the ver rises the expected domestic price rises even if the ver is not imposed

changing agricultural comparative advantage abstract special circumstances in the agricultural sector have limited the use of comparative advantage in addressing the planner s dilemma of allocating investment between industry and agriculture and in examining the doctrine of food self suffuciency a three factor model of agricultural trade extending earlier models is used to address some of these special circumstances and to formulate a theory of agricultural comparative advantage under changing economic conditions emphasis is placed on the short run fixity of sector specific capital stocks the role of qualitative differences in land natural resource endowments and on non homothetic preferences in addition to insights on agricultural comparative advantage implications for project evaluation are considered

economy wide estimates of the implications of climate change sea level rise the economy wide implications of sea level rise in 2050 are estimated using a static computable general equilibrium model this allows for a better estimate of the welfare effects of sea level rise than the common direct cost estimates and for an estimate of the impact of sea level rise on greenhouse gas emissions overall general equilibrium effects increase the welfare costs of sea level rise but not necessarily in every sector or region in the absence of coastal protection economies that rely most on agriculture are hit hardest although energy is substituted for land overall energy consumption falls with the shrinking economy hurting energy exporters with full coastal protection gdp increases particularly in regions with substantial dike building but utility falls least in regions that protect their coasts and export energy energy prices rise and energy consumption falls the costs of full protection exceed the costs of losing land the results also show direct costs the usual method for estimating welfare changes due to sea level rise are a bad approximation of the general equilibrium welfare effects previous estimates of the economic impact of sea level rise are therefore biased

weather variations and international trade in this paper i investigate the effect of weather variations in the exporter and importer countries separately as well as a the difference between weather variations in both countries on bilateral trade flows the analysis is done at the country sectoral and product levels worldwide and over the 1992 2014 period i find a negative effect of temperature variations in the exporter country and in the difference between exporter and importer countries on bilateral trade at the country level at the product level both negative and positive effects arise but the negative effect of temperature dominates the temperature effects are on the agricultural and manufacturing sectors especially in the textile and metals sectors i show that possible channels are the impact of temperature on output and labour productivity the negative impacts are larger in exporter countries that are closer to the equator that have lower quality of institutions and that export to more remote countries if countries are able to adapt to climate change the long term effects of temperature variations should be lower than the contemporaneous effect nevertheless my results on the long term effects analysis do not support this hypothesis suggesting no or very low adaptation moreover the negative effect of temperature is persistent and cumulative through several years after the temperature shock concerning precipitation variation effects they are found mainly at the product level with the positive effect dominating for the affected products

returns from research in economies with policy distortions hybrid sorghum in sudan conventional estimates of the economic return to agricultural research use market prices for the values of products and inputs on this basis economic rates of return are typically well above the cost of capital suggesting that more investment in research would be socially desirable but these estimates may be incorrect if as is often the case market prices are distorted by market failures or government policies and hence do not reflect social values this paper presents a simple partial equilibrium methodology with which to improve the measurement of social returns to research by taking account of multiple distortions in the market prices of products inputs and foreign exchange the method also takes account of variation in domestic and world prices making a product tradable in some years and nontradable in others the method is applied to the case of hageen dura 1 hd 1 sub saharan africa s first commercially successful hybrid sorghum hd 1 was released in the sudan in 1983 from the start of research in 1979 to 1992 the hd 1 breeding program had an estimated irr of 97 when all major policies in the sorghum market the fertilizer market and the exchange rate are taken into account the high rate of return to hd 1 research was due to the program s low cost and rapid payoff pointing to the potential value of small adaptive research programs taking full advantage of foreign technology and genetic material to produce locally appropriate crosses in a short period of time even in the highly distorted economies of africa such programs can yield very high payoffs

evaluating returns to agricultural research a review this paper reviews and compares the most common approaches used to evaluate public agricultural research investment ex post studies fall into two major groups a consumer and producer surplus analyses estimating average rates of return to research and b production function analyses estimating marginal rates of return to research ex ante studies fall into four groups a those using scoring models to rank research activities b those employing benefit cost analysis to establish rates of return to research c those using simulation models and d those using mathematical programming to select an optimal mix of research activities

the effects of supply shifts on producers surplus changes in the supply curve caused by technological improvements in production or changes in national policy may or may not benefit producers as a whole depending on the type of shift in the supply curve a structured analysis of different changes in the supply curve that model this situation is given and the change in producers surplus is examined depending on quantitative aspects of the supply and demand curves for supply and demand curves that are linear or power functions a small downward pivot of the supply curve will increase producers surplus only if the equilibrium point is far enough into the elastic region of the demand curve and any downward pivot of the supply curve will decrease producers surplus if the equilibrium point is in the inelastic region of the demand curve similar results are obtained for the more general case of convex supply and demand curves

some economics of global warming the greenhouse effect itself is simple enough to understand and is not in any real dispute what is in dispute is its magnitude over the coming century its translation into changes in climates around the globe and the impacts of those climate changes on human welfare and the natural environment these are beyond the professional understanding of any single person the sciences involved are too numerous and diverse demography economics biology and the technology sciences are needed to project emissions atmospheric chemistry oceanography biology and meteorology are needed to translate emissions into climates biology agronomy health sciences economics sociology and glaciology are needed to identify and assess impacts on human societies and natural ecosystems and those are not all there are expert judgments on large pieces of the subject but no single person clothed in this panoply of disciplines has shown up or is likely to this article makes an attempt to forecast the economic and social consequences of global warming due to anthropogenic greenhouse gases and attempting to prevent it

a general equilibrium analysis of climate change impacts on tourism this paper studies the economic implications of climate change induced variations in tourism demand using a world cge model the model is first re calibrated at some future years obtaining hypothetical benchmark equilibria which are subsequently perturbed by shocks simulating the effects of climate change we portray the impact of climate change on tourism by means of two sets of shocks occurring simultaneously the first set of shocks translate predicted variations in tourist flows into changes of consumption preferences for domestically produced goods the second set reallocate income across world regions simulating the effect of higher or lower tourists expenditure our analysis highlights that variations in tourist flows will affect regional economies in a way that is directly related to the sign and magnitude of flow variations at a global scale climate change will ultimately lead to a welfare loss unevenly spread across regions 2005 elsevier ltd all rights reserved

economic and welfare impacts of climate change on developing countries the impact of global climate change on developing countries is analyzed using cge multimarket models for three archetype economies representing the poor cereal importing nations of africa asia and latin america the objective is to compare the effects of climate change on the macroeconomic performance sectoral resource allocation and household welfare across continents simulations help identify those underlying structural features of economies which are the primary determinants of differential impacts these are suggestive of policy instruments to countervail undesirable effects results show that all these countries will potentially suffer income and production losses however africa with its low substitution possibilities between imported and domestic foods fares worst in terms of income losses and the drop in consumption of low income households countervailing policies to mitigate negative effects should focus on integration in the international market and the production of food crops in africa and on the production of export crops in latin america and asia

trade and the greenhouse gas emissions from international freight transport we collect extensive data on worldwide trade by transportation mode and use this to provide detailed comparisons of the greenhouse gas emissions associated with output versus international transportation of traded goods international transport is responsible for 33 percent of world wide trade related emissions and over 75 percent of emissions for major manufacturing categories including transport dramatically changes the ranking of countries by emissions per dollar of trade we systematically investigate whether trade inclusive of transport can lower emissions in one quarter of cases the difference in output emissions is more than enough to compensate for the emissions cost of transport finally we examine how likely patterns of global trade growth will affect modal use and emissions full liberalization of tariffs and gdp growth concentrated in china and india lead to transport emissions growing much faster than the value of trade due to trade shifting toward distant trading partners

technological disemployment and economic growth abstract very little early technical advance effects export expansion or import substitution because technological disemployment that much misunderstood process accompanies it that advance increases aggregate income little but merely concentrates it in fewer hands without continuing exogenous increase in aggregate demand there will be little growth this thesis is believed basic to understanding of economic growth corollaries relate to export led growth population growth and the trend during growth in the distribution of income

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

economy wide estimates of the implications of climate change human health we study the economic impacts of climate change induced change in human health viz cardiovascular and respiratory disorders diarrhoea malaria dengue fever and schistosomiasis changes in morbidity and mortality are interpreted as changes in labour productivity and demand for health care and used to shock the gtap e computable general equilibrium model calibrated for the year 2050 gdp welfare and investment fall rise in regions with net negative positive health impacts prices production and terms of trade show a mixed pattern direct cost estimates common in climate change impact studies underestimate the true welfare losses

climate change and australia s comparative advantage in broadacre agriculture australia has long been a major exporter of the products of broadacre agriculture a production system well suited to the economic and climatic conditions of the country presumably it holds a comparative advantage in these products among which grain crops and grazing livestock predominate however the future plausibility of this proposition is sensitive to the projected impacts of climate change this article develops a framework to quantify the future patterns of comparative advantage in broadacre agriculture given the projections of several global climate models we find empirical support for the conventional wisdom and note substantial resilience and robustness in australia s comparative advantage under a number of scenarios

what accounts for the growth of carbon dioxide emissions in advanced and emerging economies the role of consumption technology and global supply chain participation abstract this paper examines the driving forces behind the growth in carbon dioxide emissions in forty advanced and emerging economies between 1995 and 2008 we use the global supply chain concept introduced in timmer et al 2014 to measure co2 emissions in internationally fragmented production networks and embed the concept in structural decomposition analysis our findings suggest that rising levels of domestic consumption are related to increased carbon dioxide emissions in both advanced and emerging economies a substantial share of co2 emissions growth in emerging economies is accounted for by increased participation in global supply chains however even for countries that rapidly integrated in global production networks such as china rising domestic consumption accounts for the majority of territorial emissions

estimates of the economic effects of sea level rise regional estimates of direct cost dc are commonly used to measure the economic damages of sea level rise such estimates suffer from three limitations i values of threatened endowments are not well known ii loss of endowments does not affect consumer prices and iii international trade is disregarded results in this paper indicate that these limitations can significantly affect economic assessments of sea level rise current uncertainty regarding endowment values as reflected in two alternative data sets for example leads to a 17 percent difference in coastal protec tion a 36 percent difference in the amount of land protected and a 36 percent difference in dc globally also global losses in equivalent variation ev a welfare measure that accounts for price changes are 13 percent higher than dc estimates regional ev losses may be up to 10 percent lower than regional dc however because international trade tends to redistribute losses from regions with relatively high damages to regions with relatively low damages

the impact of global warming on agriculture a ricardian analysis reply we measure the economic impact of climate on land prices using cross sectional data on climate farmland prices and other economic and geophysical data for almost 3 000 counties in the united states we find that higher temperatures in all seasons except autumn reduce average farm values while more precipitation outside of autumn increases farm values applying the model to a global warming scenario shows a significantly lower estimated impact of global warming on u s agriculture than the traditional production function approach and in one case suggests that even without co sub 2 fertilization global warming may have economic benefits for agriculture 16 refs 5 figs 5 tabs

farmer s rights and genetic conservation in traditional farming systems abstract crop genetic resources are concentrated in some of the world s poorest farming systems these resources have been used by industrial countries without compensating farmers concerns for equity and conservation have led to proposals to protect crop genetic resources as intellectual property this paper argues that conventional intellectual property regulations e g utility patents and plant variety protection should not be used to protect crop genetic resources it suggests that farmers rights as an alternate form of intellectual property rights be used to indirectly compensate farmers by supporting genetic conservation it examines methods of in situ conservation for crop genetic resources

trade restrictions as facilitating practices abstract the effect of quantitative restrictions in oligopolistic markets is shown to depend on whether imports are substitutes or complements for domestic products in the former case they have profound effects even when set at free trade levels because they impede the ability of the foreign firm to compete in the domestic market thereby acting to facilitate collusion and raise prices and profits for this reason tariffs and quotas are fundamentally non equivalent with substitute goods when goods are complements a voluntary export restriction ver at the free trade level has no effect and tariffs and quotas are equivalent

the social costs of second best policies evidence from agricultural ghg mitigation abstract this paper investigates the social costs of second best agricultural greenhouse gas ghg mitigation policies adjustments along the land use and input intensity margins are represented within a regionalized optimization model of california crop production calibrated to economic and agronomic information second best policies relying on spatially aggregated ghg emission factors lead to small abatement efficiency losses while policies targeting a single ghg lead to moderate losses in contrast policies targeting a single input entail large abatement efficiency losses which nonetheless can be reduced by combining instruments

more on the employment effects of innovation abstract this article argues the lack of relevance to reality of the hall heffernan model specifies a model that makes the issue clear and extends beyond hagen 1982 the discussion of technological disemployment and re employment

global warming and german agriculture impact estimations using a restricted profit function this study uses the concept of shadow prices formeasuring the impacts of climate change by estimatinga restricted profit function rather than a cost or aproduction function the explanatory power of the modelis increased because of an endogenous outputstructure using low aggregated panel data on westerngerman farmers the results imply that the agricultural production process is significantly influenced by climate conditions simulation results using a 2 co2 climate scenario show positive impactsfor all regions in germany interestingly the spatialdistribution of the gains is indicating no advantagefor those regions which currently suffer frominsufficient temperature finally the importance ofan endogenous output structure is confirmed by thefinding that the desired product mix will drasticallychange

the hidden winners of renewable energy promotion insights into sector specific wage differentials abstract in light of germany s energy system transformation this paper examines differences in employment structures and wage differentials between renewable energy establishments and their sector peers to do so we have developed a novel data set by linking company level information from the german renewable energy federation with administrative establishment level data from the institute for employment research descriptive evidence shows significant differences in wages and several other characteristics between renewable energy establishments and their sector peers our estimates give evidence that human capital and other establishment level characteristics mostly explain the wage differential among manufacturers and energy providers however we find a persistent renewable energy wage premium of more than ten percent in construction installation activities and architectural engineering services we interpret this premium as a positive indirect effect of the promotion of renewable energies for the benefit of employees in renewable energy establishments within these two sectors

strategic trade practices in the presence of a ver the authors investigate the choice of competing exporters to move simultaneously or sequentially when a voluntary export restraint has introduced both asymmetry and uncertainty amongst them a restrained and an unrestrained exporter choose price strategically under the threat of a voluntary export restraint on the latter given the choice firms adopt a sequential move strategy but which leads and which follows depends upon the threat of the second voluntary export restraint the restricted firm thus sells its full quota even if this threat is low copyright 1992 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

evolving comparative advantage and the impact of climate change in agricultural markets evidence from 1 7 million fields around the world a large agronomic literature models the implications of climate change for a variety of crops and locations around the world the goal of the present paper is to quantify the macro level consequences of these micro level shocks using an extremely rich micro level data set that contains information about the productivity both before and after climate change of each of 10 crops for each of 1 7 million fields covering the surface of the earth we find that the impact of climate change on these agricultural markets would amount to a 0 26 percent reduction in global gdp when trade and production patterns are allowed to adjust since the value of output in our 10 crops is equal to 1 8 percent of world gdp this corresponds to about one sixth of total crop value

the intra country distributional impact of policies to fight climate change a survey abstract in this paper we present a survey of distributional impact analysis of environmental policies with emphasis on taxes envisaged or implemented to reduce greenhouse gas emissions ghg these policies usually aim at reducing ghg directly or indirectly however they can produce important changes in factor allocation relative prices in specific countries as well as on world markets when adopted by a large number of countries changes in welfare can be important for vulnerable groups of population in developing countries this survey reviews the evidence on the incidence of these policies in the process it shows that the computable general equilibrium cge microsimulation approach has not been fully exploited in the context

unilateral co2 reductions and carbon leakage the consequences of international trade in oil and basic materials a recursively dynamic general equilibrium model featuring six world regions with trade in energy and non energy goods is used to simulate the period from 1990 through 2100 in 10 year intervals the simulations explore the effect of unilateral action by the oecd to curb global co2 emissions unilateral cuts create incentives for free riding by non participating regions so that global emissions are reduced by less than the amount that the oecd cuts back its regional emissions carbon leakage occurs through two channels first basic materials production increases in unconstrained regions resulting in increased carbon intensity of gdp second reductions in oecd oil imports cause the world oil price to fall leading to an increased energy intensity in the non participant regions in this paper we use a general equilibrium model to assess the extent to which these two mechanisms reduce the effectiveness of oecd reductions in curbing global co2 concentrations

climate change and agriculture the role of international trade predictions of future climate and atmospheric conditions are reviewed and the implications for agriculture in different areas of the world are identified the swopsim static world policy simulation model used to evaluate the worldwide economic effects of climate change is described an economic sensitivity analysis of concurrent yield losses in major grain producing regions considering the possibility of concurrent changes in production potential elsewhere in the world is reported agricultural impacts of climate change based on three general circulation models are evaluated

climate change policy market structure and carbon leakage abstract the 1997 kyoto protocol on climate change obliges the industrialized countries to initiate the international effort of abating anthropogenic greenhouse gas ghg emissions if such an initiative is to be taken the associated competitive effects may lead to significant relocation of developed countries energy intensive production this paper examines this issue i adopt an oligopolistic structure combined with increasing returns to scale production technologies to represent the strategic interaction among the firms producing energy intensive products this representation is then embedded within a multi regional computable general equilibrium model which in turn is used for quantifying these relocational effects the results suggest that significant relocation of energy intensive industries away from the oecd may occur depending on the type of market structure with leakage rates as high as 130 in which case ghg control policies in the industrialized countries actually lead to higher global emissions

what really caused the great recession rhyme and repetition in a theme from the 1930s diagnoses of the 2008 financial crisis have invoked arguments involving real sector developments that though much debated in the 1930s had largely disappeared from the literature in recent decades prompted by these revivals the present study re examines an inter war conviction that the depression had its origins in uneven technological progress and monopolistic competition effectively reversing the induced roundaboutness view of the austrian thesis these writings noted a conflict between the resulting need for monetary accommodation and its potentially destabilising distributional consequences a common framework permits the extent of similarity in inter war and contemporary american experience to be assessed with the comparison drawing attention to the 1990s nasdaq boom and the subsequent financial behaviour of the us corporate sector consistently with the earlier literature but contrary to recent conclusions financial sector excess is seen as an aggravating factor rather than an initiating cause of the recession

why does hov fail the role of technological differences within the ec abstract this paper examines the role of international differences in production techniques in explaining the empirical failure of the heckscher ohlin vanek hov model it develops a modified hov model that relaxes the assumption of identical production techniques across countries and can be estimated using input output data of individual countries the contribution of international differences in techniques to net factor trade patterns is then isolated by comparing the performance of the strict and modified hov models the paper finds that allowing for international technique differences significantly improves the predictive power of the hov model

food self sufficiency comparative advantage and agricultural trade a policy analysis matrix for chinese agriculture revised china s rapid economic growth and gradual transition toward a market economy have brought about significant changes in production and consumption patterns and trade behavior in agriculture in this study the authors assess the comparative advantage and protection of china s major agricultural crops using a modified policy analysis matrix ipami and data from 1996 to 1998 results strongly suggest that china has a comparative advantage in labor intensive crops and a disadvantage in land intensive crops

trade and carbon taxes we study various scenarios for taxing emissions of carbon dioxide c02 the question is how carbon tax policies will perform given interna tional trade if countries adopt different tax rates we investigate this question quantitatively using cim earth a newly developed open source computable general equilibrium cge model since climate change is a function of global c02 emissions an efficient strategy for control ling emissions would be to impose the same price wherever they occur such an approach presents a free riding problem however because nations have an incentive not to comply while gaining the ben efits of reduced emissions elsewhere moreover because of distributive concerns and claims about

research needs and challenges in the few system coupling economic models with agronomic hydrologic and bioenergy models for sustainable food energy and water systems on october 12 13 a workshop funded by the national science foundation was held at iowa state university in ames iowa with a goal of identifying research needs related to coupled economic and biophysical models within the few system approximately 80 people attended the workshop with about half representing the social sciences primarily economics and the rest from the physical and natural sciences the focus and attendees were chosen so that findings would be particularly relevant to sbe research needs while taking into account the critical connectivity needed between social sciences and other disciplines we have identified several major gaps in existing scientific knowledge that present substantial impediments to understanding the few system we especially recommend research in these areas as a priority for future funding 1 economic models of decision making in coupled systems deliberate human activity has been the dominant factor driving environmental and land use changes for hundreds of years while economists have made great strides in modeling and understanding these choices the coupled systems modeling literature with some important exceptions has not reflected these contributions several paths forward seem fruitful first baseline economic models that assume rationality can be used much more widely than they are currently moreover the current generation of iams that include rational agents have emphasized partial equilibrium studies appropriate for smaller systems to allow this approach to be used to study larger systems the potential for and consequences of general equilibrium effects should be studied as well second it is important to address shortcomings in these models of economic decision making valuable improvements could be gained from developing coupled models that draw insights from behavioral economics many decision makers deviate systematically from actions that would be predicted by strict rationality but very few iams incorporate this behavior potentially leading to inaccurate predictions about the effects of policies and regulations improved models of human adaptation and induced technological change can also be incorporated into coupled models particularly for medium to long run models decisions about adaptation and technological change will have substantial effects on the conclusions and policy implications but more compelling methods for incorporating these changes into modeling are sorely needed in addition some economic decisions are intrinsically dynamic yet few coupled models explicitly incorporate dynamic models economic models that address uncertainty in decision making are also underutilized in coupled models of the few system 2 coupling models across disciplines despite much recent progress established models for one component of the few system often cannot currently produce outcomes that can be used as inputs for models of other components this misalignment makes integrated modeling difficult and is especially apparent in linking models of natural phenomena with models of economic decision making economic agents typically act to maximize a form of utility or welfare that is not directly linked to physical processes and they typically require probabilistic forecasts as an input to their decision making that many models in the natural sciences cannot directly produce we believe that an especially promising approach is the development of bridge models that convert outputs from one model into inputs for another such models can be viewed as application specific reduced form distillations of a richer and more realistic underlying model ideally these bridge models would be developed in collaborative research projects involving economists statisticians and disciplinary specialists and would contribute to improved understanding in the scientific discipline as well 3 model validation and comparison there is little clarity on how models should be evaluated and compared to each other both within individual disciplines and as components of larger iams this challenge makes larger integrated modeling exercises extremely difficult some potential ways to advance are by developing statistical criteria that measure model performance along the dimensions suitable for inclusion in an iam as well as infrastructure and procedures to facilitate model comparisons focusing on the models out of sample distributional forecasting performance as well as that of the iam overall is especially promising and of particular importance moreover applications of iams tend to estimate the effect of hypothetical future policy actions but there have been very few studies that have used these models to estimate the effect of past policy actions these exercises should be encouraged they offer a well understood test bed for the iams and also contribute to fundamental scientific knowledge through better understanding of the episode in question the retrospective nature of this form of analysis also presents the opportunity to combine reduced form estimation strategies with the iams as an additional method of validation

testing two trade models in latin american agriculture abstract the heckscher ohlin and markusen models state that countries export the goods intensive in the use of their relatively abundant factor latin american agricultural trade is consistent with both models the paper then shows that latin american agricultural trade is primarily explained by country differences in relative factor abundance between countries rather than differences in technology this findings does not reject the heckscher ohlin model but rejects one of markusen s models

the convention on biological diversity and agriculture implications and unresolved debates1 summary the convention on biological diversity addresses two controversies that surround plant genetic resources pgrs one debate has been over property rights governing pgrs and the distribution of benefits from their use the second has been over the adequacy of measures to maintain crop genetic diversity this paper examines how these two debates are linked and reviews previous multilateral attempts to address them the convention signals wider international acceptance of stricter property rights over pgrs and the need for multilateral assistance for pgr conservation however current proposals to implement the convention appear too limited in scope to achieve their stated conservation objectives while several areas of controversy remain these include debates over i intellectual property protection for biological inventions ii control over pgrs in international gene banks iii the international biosafety protocol regulating biotechnology iv mechanisms to finance pgr conservation and v the allocation of funds between in situ and ex situ conservation q 1998 elsevier science ltd all rights reserved

resource supplies and changing world agricultural comparative advantage abstract this paper advances consideration of the heckscher ohlin h o theory of comparative advantage to agriculture in a dynamic setting the dynamic relationship among trade flows resource supplies and factor contents is studied the view that special circumstances in the agricultural sector render the h o theory inapplicable as a guide to agricultural trade is challenged consistent with the h o theory the results suggest that changing world patterns of resource abundance are an important explanation of the evolving structure of world trade in agriculture commodities

returns to public investments in agriculture with imperfect downstream competition a multiple market framework is developed to measure the size and distribution of research benefits the model considers an upstream raw product market and a downstream finished product market and allows for imperfect competition in the intermediary food processing sector a central conceptual result is derived an increase in raw product output is a sufficient condition for costreducing innovations in the farm sector to increase social welfare a special case of linear farm supply and isoelastic processing production functions reveals that necessary conditions for welfare to decrease are a convergent farm supply shift an oligopsonistic upstream market configuration and increasing returns to scale processing technology a basic goal of public agricultural research is to reduce the costs of farm production toward this end governments have invested considerable resources to improve basic scientific knowledge develop novel technologies and facilitate the adoption of modern plant varieties and farming methods economists have generally concluded that public investments in agriculture have achieved remarkable success in lowering the marginal cost of farm production due in large part to the effectiveness of land grant research and extension activities chavas and cox cochrane as a result of these cost changes public agricultural investments have been shown to yield impressive social rates of return in numerous studies for a survey of this literature see alston norton and pardey several recent papers have shown that imperfect competition in the downstream processing sector can affect both the size and the distribution of welfare changes dryburgh and doyle consider the impact of technical innovation in a multimarket study of the british dairy industry under alternate downstream in

global economic growth and agricultural land conversion under uncertain productivity improvements in agriculture we study how stochasticity in the evolution of agricultural productivity interacts with economic and population growth at the global level we use a two sector schumpeterian model of growth in which a manufacturing sector produces the traditional consumption good and an agricultural sector produces food to sustain contemporaneous population agriculture demands land as an input itself treated as a scarce form of capital in our model both population and sectoral technological progress are endogenously determined and key technological parameters of the model are structurally estimated using 1960 2010 data on world gdp population cropland and technological progress introducing random shocks to the evolution of total factor productivity in agriculture we show that uncertainty optimally requires more land to be converted into agricultural use as a hedge against production shortages and that it significantly affects both optimal consumption and population trajectories

profitability of export restraint this paper analyzes the effect of quotas or voluntary export restraints upon each producer s profits in the case of an oligopoly with one foreign producer in this oligopoly all producers including the foreign producer can get greater profits under some protective quotas than under no restraints furthermore the optimal export restraint for the foreign producer with a low marginal cost is smaller than his optimal export under no restraints accordingly export restraints may be sought by the foreign producer as a strategic behavior to increase profits

on the spatial economic impact of global warming we propose a dynamic spatial theory to analyze the geographic impact of climate change agricultural and manufacturing firms locate on a hemisphere trade is costly firms innovate and technology diffuses over space emissions from energy used in production contribute to the atmospheric stock of carbon which increases temperature warming differs across latitudes and its effect on productivity varies across sectors we calibrate the model to analyze how climate change affects the spatial distribution of economic activity trade migration growth and welfare we assess quantitatively the impact of migration and trade restrictions energy taxes and innovation subsidies

market distortions and benefits from research the benefits from cost reducing research and their distribution under a range of price policies are compared with those that would arise in the absence of the policies while any price policy affects the distribution of research benefits the net national or world benefits may be reduced lef unchanged or increased depending on the nature of the policy and the significance of the country in the world market for the commodity some implications for decisions on price policies and for distortions in incentives for the allocation of resources to research are raised

import quotas and vers a comparative analysis in a three country framework abstract because a ver is inherently discriminatory the traditional two country analysis comparing it to a quota is inadequate this paper adopts a general equilibrium three country approach to compare tariffs quotas and vers a quota equivalent ver is defined alternatively in terms of quantity or price the welfare of the importing country is higher under a quota and that of the non restricted exporter is higher under a ver the welfare comparison for the ver restricted country is ambiguous a result which is at variance with conventional wisdom

climate change and adaptation the case of nigerian agriculture the present research offers an economic assessment of climate change impacts on the four major crop families characterizing nigerian agriculture the evaluation is performed by shocking land productivity in a computable general equilibrium model tailored to replicate nigerian economic development up to 2050 the detail of land uses in the model has been increased by differentiating land types per agro ecological zones uncertainty about future climate is captured using as inputs yield changes computed by a crop model under ten general circulation models runs climate change turns out to be negative for nigeria in the medium term with production losses and increase in crop prices higher food dependency on foreign imports and gdp losses in all the simulations after 2025 in a second part of the paper a cost effectiveness analysis of adaptation in nigerian agriculture is conducted the adaptation practices considered are a mix of cheaper soft measures and more costly hard irrigation expansion the main result is that the cost effectiveness of the whole package depends crucially on the possibility of implementing adaptation by exploiting low cost opportunities which show a benefit cost ratio larger than one in all the climate regimes

the calculation of returns to research in distorted markets reply abstract most of the emperical literature calculating rates of return to publicly sponsored research assumes that research is the only relevant government intervention for most countries this assumption is untenable this paper shows that improperly measuring government inducedmarket distortions can severely bias research rate of return calculations if the interaction between successful research and other government interventions increases the cost of the other interventions then neglecting market distortions unambigously increases the calculated rate of return three examples of government induced distortions show that the magnitude of the upward bias in calculated rates of return can be extremely large in some cases more than 100 percentage points a normative implication is that governments should account for interactions between research and price interventions when determining research support levels a positive implication is that existing government research funding patterns are more readily explainable as reasonable behavior by a government that accounts for these interactions

genetic improvements in major us crops the size and distribution of benefits the distribution of welfare gains of genetic improvements in major us crops is estimated using a world agricultural trade model multi market welfare estimates were 75 larger than estimates based on the price exogenous change in revenue method frequently used by plant breeders annual benefits of these genetic improvements range from us 400 600 million depending on the supply shift specification of this 44 60 accrues to the us 24 34 accrues to other developed countries developing and transitional economies capture 16 22 of the welfare gain the global benefits of a one time permanent increase in us yields are us 8 1 billion discounted at 10 and us 15 4 billion discounted at 5 gains to consumers in developing and transitional economies range from us 6 1 billion 10 discount rate to us 11 6 billion 5 discount rate

the distribution of benefits from technical change among classes of consumers and producers an ex anteanalysis of beans in brazil abstract because new agricultural technology in developing countries has sometimes bypassed small farmers who are an important social group in low income countries design of technology specifically appropriate to small farmers has been advocated as a policy goal this paper appraises the comparative returns to investment in small farm biased scale neutral and large farm biased technology for bean production in brazil a consumer surplus model is developed to estimate the distribution of benefits among producing sectors and classes of consumers while previous studies have relied on geometrical approximations to measure economic benefits as the area under the supply shifts here an exact analytic solution is obtained by integrating from the supply axis scale neutral technology leads to significant small farmer benefits while maximizing benefits to consumers large farm biased technology results in less benefits to small farmers and consumers and only minor gains to large farmers when compared to scale neutral technology small farm biased technology produces the greatest gains to small farmers but the lowest level of benefits to consumers

skill transferability migration and development evidence from population resettlement in indonesia we use a natural experiment in indonesia to provide causal evidence on the role of location specific human capital and skill transferability in shaping the spatial distribution of productivity from 1979 1988 the transmigration program relocated two million migrants from rural java and bali to new rural settlements in the outer islands villages assigned migrants from regions with more similar agroclimatic endowments exhibit higher rice productivity and nighttime light intensity one to two decades later we find some evidence of migrants adaptation to agroclimatic change overall our results suggest that regional productivity differences may overstate the potential gains from migration