how much damage will climate change do recent estimates two reasons to be concerned about climate change are its unjust distributional impact and its negative aggregate effect on economic growth and welfare although our knowledge of the impact of climate change is incomplete and uncertain economic valuation is difficult and controversial and the effect of other developments on the impacts of climate change is largely speculative the authors find that poorer countries and people are more vulnerable than are richer countries and people a modest global warming is likely to have a net negative effect on poor countries in hot climates but may have a net positive effect on rich countries in temperate climates if one counts dollars the world aggregate may be positive if one counts people the world aggregate is probably negative negative impacts would become more negative and positive impacts would turn negative for more substantial warming the marginal costs of carbon dioxide emissions are uncertain and sensitive to assumptions that partially reflect ethical positions but are unlikely to be larger than 50 per tonne carbon

robust trading mechanisms we consider the problem of designing a trading institution for a single buyer and seller when their valuation of the good is private information it is shown that posted price mechanisms are essentially the only mechanisms such that each trader has a dominant strategy a posted price mechanism is one where a price is posted in advance and trade occurs if and only if all traders agree to trade

spatial cost benefit thinking in multi functional forestry towards a framework for spatial targeting of policy interventions abstract many countries now actively encourage land use change for the provision of multiple benefits specifically including non market benefits often such policies have been poorly designed because of a lack of understanding of the spatial distribution of the potential costs and especially non market benefits from land use change as with market goods the potential yield of non market goods and services from land use can be highly spatially variable in recent years more and more studies on the economic aspects of natural resources have started to make use of geographical information systems gis what is yet lacking is the systematic adoption of a framework for the spatial targeting of policy interventions which can be used to improve decision making in terms of effectiveness efficiency equity or public acceptability this paper uses existing studies in forestry to present such a framework and discusses its potential uses and limitations as a new standard tool to inform multi functional land use decisions

strategy proof exchange we consider the allocation of goods in exchange economies with a finite number of agents who may have private information about their preferences in such a setting standard allocation rules such as walrasian equilibria or rational expectations equilibria are not compatible with individual incentives we characterize the set of allocation rules which are incentive compatible or in other words the set of strategy proof social choice functions social choice functions which are strategy proof are those which can be obtained from trading according to a finite number of pre specified proportions the number of proportions which can be accommodated is proportional to the number of agents such rules are necessarily inefficient even in the limit as the economy grows

welfare specifications and optimal control of climate change an application of fund the sensitivity of the optimal control of carbon dioxide emissions to the specification of the social welfare function is systematically explored using the fund model increasing risk aversion emphasises climate change damages relative to emission reduction costs but at the same time increases the discount rate of consumption without international co operation the discount rate effect dominates so that optimal control decreases with increasing risk aversion with international co operation optimal control first increases then decreases with increasing risk aversion since climate change falls heaviest on the poor optimal control increases with increasing inequity aversion full fledged intergenerational welfare functions on the one hand emphasise climate change damages but on the other hand place more weight on current poorer generations in fund the two tendencies almost cancel

parental benefits from intergenerational coresidence empirical evidence from rural pakistan this paper explains the negative correlation between the days of work reported by fathers in rural pakistani households and the incomes earned by their coresident adult sons thereby contributing to research on the benefits from intergenerational coresidence i find that the decline in fathers days of work that accompanies increases in sons incomes primarily results because such income is used to finance expenditures on household public goods such as consumer durables and ceremonies empirical tests reject most alternative explanations of the benefits of coresidence including the belief that sons contribute to fathers wealth

the connection between public transfers and private interfamily transfers abstract this paper investigates the anti poverty effectiveness of public transfers taking private transfer responses into account widespread altruistically motivated private transfers would neutralize the distributional impact of public transfers but exchange motivated transfers can reinforce the effects of public transfers on the distribution of economic well being the common technique for gauging anti poverty effectiveness subtracting public transfers from other income and measuring the poverty rate counterfactual yields results that are close to a more complex procedure that takes private transfer responses into account and some of the empirical findings suggest an exchange rather than altruistic motive for private transfers indicating that the effects of public transfers can be magnified by private behavior this is an exact reversal of the prediction that public transfers merely supplant private ones

implementation in differential information economies abstract we consider the problem of implementation of social choice correspondences in differential information economies we provide necessary conditions for implementation and slightly stronger conditions which are sufficient to guarantee implementation

the strategic bequest motive although recent research suggests that intergenerational transfers play an important role in aggregate capital accumulation our understanding of bequest motives remains incomplete we develop a simple model of strategic bequests in which a testator influences the decisions of his beneficiaries by holding wealth in bequeathable forms and by conditioning the division of bequests on the beneficiaries actions the model generates falsifiable empirical predictions that are inconsistent with other theories of intergenerational transfers we present econometric and other evidence that strongly suggests that bequests are often used as compensation for services rendered by beneficiaries

inter vivos transfers and intergenerational exchange the surge of interest in intergenerational transfers in the past decade has sparked a debate over the motivation for them are transfers given out of altruism or part of an exchange while each motive is probably at work to some extent we know little about whether one motive predominates the question is relevant for issues concerning public income redistribution and inequality in the family but despite its importance empirical evidence about motives is scarce because of limited data we investigate a new data set the national survey of families and households which remedies many of the shortcomings of other data sets containing private transfer information we find that empirical patterns for inter vivos transfers i e transfers between living persons are more consistent with exchange than altruism

how well do children insure parents against low retirement income an analysis using survey data from urban china abstract as population aging becomes more pronounced in the developing world the uneven implementation of social safety nets raises important questions as to how well traditional family based mechanisms insure elderly incomes when pension systems fail using a unique dataset from a recent household survey conducted in urban china we find evidence that private transfers respond to low household income of retired workers when income falls below the poverty line this finding is consistent with an altruistic motive for transfers at low levels of household income at the same time however the transfer response to elderly pre transfer income is not sufficient to fully cover shortfalls that arise with severe pension arrears and low retirement income

intergenerational household formation female labor supply and informal caregiving a bargaining approach children s provision of in kind services to their elderly parents informal caregiving represents an important form of economic transfers to the elderly in this paper we develop and estimate a joint model of informal caregiving and labor force participation decisions of adult daughters who have a frail elderly parent in a broader framework of intergenerational household formation parent and daughter agree to a nash bargaining rule as the solution to the household formation and intrahousehold decision making process however rather than severed relationships the threat point is given by a noncooperative equilibrium defined in terms of voluntary contributions toward a public good the parental well being maximum likelihood parameter estimates derived from the simultaneous multiequation endogenous switching model are generally consistent with expectations our results indicate that competing demands on daughters time reduce both coresidence and informal caregiving we also find that intergenerational coresidence is an important mode of assistance to elderly persons a simulation based on the estimated parameters suggests that public programs designed to meet the long term care needs of elderly persons by subsidizing formal home care services may have substantial effects on intergenerational living and care arrangement decisions

monetary transfers from children and the labour supply of elderly parents evidence from vietnam in the absence of a broad based pension scheme the elderly in developing countries may rely on monetary transfers made by their children and on their own labour supply this article examines whether monetary transfers from children help to reduce elderly parents need to work taking the possible endogeneity of children s transfers in the parents labour supply into account and using maximum likelihood methods and vietnamese data we find that monetary transfers help the elderly cope with risks associated with old age or illness at the same time however monetary transfers are not sufficient to fully substitute for parents labour supply

equitable cost benefit analysis of climate change greenhouse gas emissions and vulnerability to climate change show a strong negative correlation this is the moral issue at the heart of the climate problem however little attention has been paid to this in the literature see banuri et al 1996 for an overview the literature on equity issues in climate change is largely confined to the distribution of emissions reduction targets this literature takes the need to reduce greenhouse gas emissions for granted and takes a parametric approach to the required reductions on the other hand the literature that tries to derive how much emissions abatement is desirable largely ducks the equity issue this paper is an attempt to combine the two problems

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

equitable cost benefit analysis of climate change policies the literature of welfare maximising greenhouse gas emission reduction strategies pays remarkably little attention to equity this paper introduces three ways to consider efficiency and equity simultaneously the first method inspired by kant and rawls maximises net present welfare without international cooperation as if all regions share the fate of the region affected worst by climate change optimal emission abatement varies greatly depending on the spatial and temporal resolution that is the grid at which maximum impact is defined the second method is inspired by varian s no envy emissions are reduced so as to equalise total costs and benefits of climate change over all countries of the world and over all time periods emission reductions are substantial this method approximately preserves the inequities that would occur in a world without climate change the third method uses non linear aggregations of welfare the utilitarian default is linear in a cooperative setting this method cannot distinguish between sources of inequity the higher the aversion to inequity the higher optimal greenhouse gas emission reduction

nonmarket institutions for credit and risk sharing in low income countries the design credit and risk institutions in low income countries provides one of the most exciting testing grounds for theories of contracting with imperfect information and limited enforcement this paper reviews some of the recent literature with a special focus on nonmarket institutions that cope with risk and provide credit this literature attempts to bring together insights from economic theory especially information economics contract theory and mechanism design theory however it is also applied being motivated by the circumstance of the poor countries that their authors have visited and studied

implementation in economies with a continuum of agents we study a general implementation problem for exchange economies with a continuum of players and private information and test the robustness of the results for sequences of approximating finite economies assuming that the designer knows the distribution of the characteristics in the economy we consider continuous and unique implementation in both its equilibrium and dominant strategies versions and obtain results for general self selective first and second best allocations an upper hemicontinuity property of bayesian equilibria of approximating economies for continuous mechanisms is demonstrated using this we can for example conclude that if a given continuous mechanism implements uniquely a walrasian allocation in the continuum economy then all bayesian equilibria of large approximation economies will with probability close to one yield an allocation which is almost ex post pareto optimal

on the generic nonoptimality of dominant strategy allocation mechanisms a general theorem that includes pure exchange economies it is shown that if an economy s participants cannot be separated into groups across which there are no potentially conflicting interests i e if the economy is indecomposable then every continuous truth dominant allocation mechanism will attain nonoptimal allocations on an open dense set of preference profiles classical edgeworth box exchange economies economies with no externalities and no production but with arbitrary numbers of consumers and goods as well as economies with public goods and economies with other kinds of externalities are all shown via simple arguments to be indecomposable the results are extended to cover nonrevelation mechanisms copyright 1990 by the econometric society

income smoothing and consumption smoothing one way that risk averse households protect consumption levels is to borrow and use insurance mechanisms another way common in low income economies is to diversify economic activities and make conservative production and employment choices households thus tend toward limiting exposure only to shocks that can be handled with available credit and insurance typically both types of mechanisms are studied independently but much more can be learned by studying them together first we obtain a more complete picture of risks costs and insurance possibilities second it opens the way to considering biases in standard tests of credit and insurance

asymptotic efficiency in large exchange economies with asymmetric information the authors provide conditions on an exchange economy with asymmetric information that guarantee that when the economy is replicated sufficiently often there will be an allocation that is incentive compatible individually rational and nearly efficient the main theorem covers both the case in which aggregate uncertainty remains when the economy is replicated and the case in which replication eliminates aggregate uncertainty in addition the authors demonstrate how their theorem does or does not apply to standard asymmetric information problems such as the buyer s bid double auction problem akerlof s lemons problem and insurance with asymmetric information copyright 1992 by the econometric society

consumption insurance an evaluation of risk bearing systems in low income economies the hypothesis of full risk sharing can be taken to data from low income countries and evaluate formal and informal financial systems in many contexts idiosyncratic risks are high so credit insurance arrangements could be beneficial statistical tests reveal that households in southern india take advantage of these possibilities villages in cote d ivoire and countries in thailand do not do as well the paper includes an empirical description of the devices used to smooth consumption and a theoretical discussion of private information and incentives on ideal operating systems the full information and mechanism design frameworks provide benchmarks for policy analysis

old age benefits and retirement decisions of rural elderly in brazil abstract i estimate the impact of social security benefits on retirement decisions of rural workers by studying changes in the rules governing old age benefits for rural workers in brazil i focus on a reform implemented in 1991 which reduced the minimum eligibility age increased benefits and extended the program to non heads of households because those benefits come with no strings attached they are not means or retirement tested any behavioral response is a pure income effect the main finding of the paper is that access to old age benefits is a strong determinant of retirement of rural workers in brazil receiving old age benefits increases the probability of not working by about thirty eight percentage points and reduces total hours per week by 22 h

what do we learn from the weather the new climate economy literature a rapidly growing body of research applies panel methods to examine how temperature precipitation and windstorms influence economic outcomes these studies focus on changes in weather realizations over time within a given spatial area and demonstrate impacts on agricultural output industrial output labor productivity energy demand health conflict and economic growth among other outcomes by harnessing exogenous variation over time within a given spatial unit these studies help credibly identify i the breadth of channels linking weather and the economy ii heterogeneous treatment effects across different types of locations and iii nonlinear effects of weather variables this paper reviews the new literature with two purposes first we summarize recent work providing a guide to its methodologies datasets and findings second we consider applications of the new literature including insights for the damage function within models that seek to assess the potential economic effects of future climate change jel c51 d72 o13 q51 q54

technologies energy systems and the timing of co2 emissions abatement an overview of economic issues abstract this paper provides an overview of economic issues involved in timing limitations on co2 emissions from energy systems it highlights issues relating to technology availability development and diffusion and the inertia of energy systems as being particularly important the paper sets this in the context of wider uncertainties surrounding the problem and briefly considers other aspects relevant to timing the paper is stimulated by the debate in the usa about optimal abatement paths in particular recent claims that it would be economically preferable to defer such abatement action in favour of measures that support technology development but do not affect emission trends for many years this paper categorizes the various economic issues involved and concludes that for each economic argument that has been advanced to justify deferring emission constraints there are counter vailing economic arguments that could be used in support of rapid near term emissions abatement rational policy lies between these extremes a policy of deferring all emissions abatement exposes economic systems and industries as well as the environment to significantly greater costs and risks than those arising from a more balanced approach furthermore the modelling studies that have been used to justify deferring emissions abatement do so because they embody the economic factors favourable to delay and largely neglect the countervailing issues to the point where their results have little relevance to the overall problem of timing emissions abatement

economic growth and global warming a model of multiple equilibria and thresholds abstract we presume a simple endogenous growth model where global warming affects economic growth and analyze the dynamics of the competitive economy and of the social optimum our regulatory instrument is an emission tax rate we demonstrate that for certain values of the emission tax ratio the competitive economy exhibits multiple equilibria and a threshold may exist that separates the domains of attraction for the growth paths there exist paths to high growth rates and low temperature and low growth rates and high temperature for the planner s problem the long run equilibrium is unique unless the damage of global warming is very small

spatial and temporal efficiency in climate policy applications of fund fund is an integrated assessment model of the interactions between climate and economy nine world regions emit greenhouse gases and suffer damages from climate change a number of greenhouse gas emission reduction policies are compared including optimal and cost effective strategies strategies with early and late abatement and strategies with and without international co operation the analyses confirm that co operation matters resulting in substantially lower costs or higher welfare the real commitments of policy targets based on an absolute level e g 1990 emissions are hard to estimate because of the uncertainties in the baseline postponing action conflicts with minimising costs and maximising welfare but so does sharp emission reduction at the short term as proposed in the kyoto protocol

technological change in economic models of environmental policy a survey this paper provides an overview of the treatment of technological change in economic models of environmental policy numerous economic modeling studies have confirmed the sensitivity of mid and long run climate change mitigation cost and benefit projections to assumptions about technology costs in general technical progress is considered to be a noneconomic exogenous variable in global climate change modeling however there is overwhelming evidence that technological change is not an exogenous variable but to an important degree endogenous induced by needs and pressures hence some environmenteconomy models treat technological change as endogenous responding to socio economic variables three main elements in models of technological innovation are i corporate investment in research and development ii spillovers from r d and iii technology learning especially learning by doing the incorporation of induced technological change in different types of environmental economic models tends to reduce the costs of environmental policy accelerates abatement and may lead to positive spillover and negative leakage

motives for private income transfers private income transfers are becoming increasingly recognized as a key aspect of the u s economy the majority of private income transfers occur inter vivos i e between living persons but very little is known about this type of transfer behavior this paper tests alternative hypotheses concerning motivation for inter vivos transfers two motives are considered altruism and exchange evidence presented here casts doubt on the altruistic model of transfer behavior observed patterns for inter vivos transfers are more consistent with exchange related motives this finding has important implications for the effects of public transfer programs on the distribution of economic well being

the joint determination of household membership and market work the case of young men except in special cases market work and household membership are jointly chosen a nash bargaining model of family behavior is used to specify stochastic structural relationships two indirect utility functions and a market and a reservation wage function that jointly determine work consumption and household membership the maximum likelihood estimates of the implied trinomial probit model differ sharply from those obtained when either market work or household membership is taken as exogenous this application to white male youths from the national longitudinal surveys shows the insurance function of families parents insure their sons against poor market opportunities

parental altruism and inter vivos transfers theory and evidence this paper uses psid data on the extended family to test whether inter vivos transfers from parents to children are motivated by altruism specifically the paper tests whether an increase by one dollar in the income of parents actively making transfers to a child coupled with a one dollar reduction in that child s income results in the parents increasing their transfer to the child by one dollar this restriction on parental and child transfer income derivatives is derived for the standard altruism model augmented to include uncertainty and liquidity constraints these additional elements pin down the timing of inter vivos transfers the method used to estimate income transfer derivatives takes into account unobserved heterogeneity across families in the degree of altruism the findings strongly reject the altruism hypothesis redistributing one dollar from a recipient child to donor parents leads to less than a 13 cent increase in the parents transfer to the child far less than the one dollar increas

a regional dynamic general equilibrium model of alternative climate change strategies outcomes and noncooperative equilibria this study finds that cooperative policies show much higher levels of emissions reductions than do noncooperative strategies that there are substantial differences in the levels of controls in both the cooperative and the noncooperative policies among different countries and that high income countries may be the major losers from cooperation jel h41 q4 q2 q20

the damage costs of climate change towards a dynamic representation economic assessments of climate change impacts are commonly presented as the effect of a climate change associated with a doubling of the atmospheric concentration of carbon dioxide on the current economy this paper is an attempt to express impact as a function of both climate change and socio economic change with regard to climate change issues discussed are level versus rate of change speed of adaptation speed of restoration and value adjustment and symmetry with regard to socio economic change agriculture migration and the valuation of intangible losses are addressed uncertainty and higher order impacts are treated briefly it is qualitatively argued and quantitatively illustrated that these issues matter a great deal for the damage profile over the next century a damage model based on my best guesses is presented in the appendix

short term decisions under long term uncertainty the behaviour of future policy makers substantially influences future greenhouse gas emissions uncertainty about the motives of future policy makers may thus strongly influence the climate policy strategies of current policy makers analytical and numerical analyses in this paper confirm this hypothesis if current policy makers want to constrain emissions accumulated over a prolonged period of time and if future policy makers tend with a certain chance to a less ambitious climate policy then current policy makers should intensify their efforts to reduce emissions and the cost of emission reduction in this setting if current policy makers want to meet a cumulative emission contraint in expectation then the preferred policy trajectory does not qualitatively deviate from one suggested by a standard cost effective trajectory if however the constraint is to be met with a certain probability then the importance of early action is enhanced relative to that of postponed action costs substantially increase if current policy makers want to set long term goals without the full cooperation of future policy makers