overlapping generations and environmental control abstract this paper sets forth a continuous time olg model in order to analyze intertemporal trade offs in the use of environmental resources this theoretical framework proves to be particularly appropriate in examining the externalities arising from consumer heterogeneity and disconnectedness across generations we characterize the trade off between capital accumulation and the environment and derive the conditions for an optimal fiscal policy the role of government intervention is twofold first it has to achieve intergenerational equity compatibly with a time consistent social welfare criterion second it has to correct the intertemporal market failures due to the selfish behavior of each generation

sustainability policy and environmental policy a theoretical representative agent economy with a depletable resource stock polluting emissions and productive capital is used to contrast environmental policy which internalises externalised environmental values with sustainability policy which achieves some form of intergenerational equity the obvious environmental policy comprises an emissions tax and a resource stock subsidy each equal to the respective external cost or benefit sustainability policy comprises an incentive affecting the choice between consumption and investment and can be a consumption tax capital subsidy or investment subsidy or a combination thereof environmental policy can reduce the strength of the sustainability policy needed more specialised results are derived in a small open economy with no environmental effects on utility

intergenerational equity the capital environment trade off abstract this paper examines the trade off between capital accumulation and environmental quality that determines an intergenerationally equitable program according to the rawls maximin criterion this trade off is explored by an analysis of regular maximin programs in the framework developed by brock this results in a constant utility path supported by competitive prices with government imposed effluent charges and environmental rentals sufficient conditions for a regular maximin path to satisfy a hartwick rule in deciding on the combination of capital and environmental quality left to future generations are given

what makes basic research economically useful abstract economic analysis has helped us understand the strong economic dimension in the explosive growth of science and more recently the reasons for continuing public subsidies however the growing domination of the market failure approach has led to the analytical neglect of two major questions for policy makers how does science contribute to technology are the technological benefits from science increasingly becoming international on the former too much attention has been devoted to the relatively narrow range of scientific fields producing knowledge with direct technological applications and too little to the much broader range of fields the skills of which contribute to most technologies on the latter national systems of science and of technology remain closely coupled in most major countries in spite of the technological activities of large multinational firms empirical research is needed on concentration scale and efficiency in the performance of basic research where techniques and insights from the applied economics of industrial r d are of considerable relevance there is no convincing evidence so far of unexploited economies of scale in basic research this evidence shows that many policies for greater selectivity and concentration in basic research have been misconceived economists and other social scientists could help by formulating more persuasive justifications for public subsidy for basic research and by making more realistic assumptions about the nature of science and technology

environmental tax policy and intergenerational distribution abstract we study the effects of environmental taxation within the context of an overlapping generations model the quality of the environment is modelled as a durable consumption good introduction of the environmental tax harms old existing generations and benefits young existing generations as well as all future generations increasing the tax in a pareto improving manner is easier the higher the pre existing tax the reverse holds if tax policy is decided by majority rule a suitably designed bond policy can be used to redistribute the efficiency gains due to the internalisation of environmental externalities across the generations

how valuable is patent protection estimates by technology field i present evidence on the private value of patent rights in france for different technology fields and nationalities of ownership using nonparametric techniques and a parametric model of patent renewal i find that the distribution of the value of patent rights is highly skewed that patent protection is a significant but not the major source of private returns to r d and that these characteristics vary across technology fields i compute the r d cash subsidy that is equivalent to the value of patent rights measure the variations in value of time technology fields and nationalities and show that these differences are correlated with patent grant rates

publicly funded r d programs and survival of patents i apply a survival model to a detailed data set of swedish patents to estimate how different financing factors affect the likelihood of patent renewal since the owners know more about the patents than potential external financiers there is a problem of asymmetric information to overcome this sweden has for a long time relied on government support rather than private venture capital pvc in the empirical analysis two kinds of government loans are unbundled the empirical results show that patents which have received soft government loans in the r d phase have a higher probability of expiring than patents without such financing but patents that have received more market oriented government loans during the commercialization phase are renewed for as long as other commercialized patents this finding suggests that rather than bad choices of projects it is the nature of the contract terms that explains the low renewal of some patents with government financing

sustainability and technical progress a rigorous model connects together the following three basic concepts 1 sustainability meaning the generalized future power of an economy to consume over time 2 green nnp meaning a current measure of national income that subtracts off from gnp not just depreciation of capital but also more generally depletion of environmental assets evaluated at current efficiency prices 3 technological progress meaning a projection onto the future of the so called solow residual a simple general formula is derived some crude calculations suggest a possibly strong effect of the residual which hints that our best present estimates of long term sustainability may be largely driven by predictions of future technological progress

environmental valuation under sustainable development environmentalism has evolved since the 1960 s from a concern with the preservation of wilderness in the american experience to a concern over pollution of human habitat throughout the industrialized world northern anxiety spread to the loss of tropical rainforests and biodiversity in the south where environmentalism evolved further in an encounter with indigenous interpretations conditions and priorities by the late 1980 s climate change emerged as a central issue in a now global discourse on the relationship between environment and development the principle of sustainable development that current needs are to be met as fully as possible while ensuring that the life opportunities of future generations are undiminished relative to present is now widely accepted this paper illustrates that incorporating environmental values per se in decision making will not bring about sustainability unless each generation is committed to transferring to the next sufficient natural resources and capital assets to make development sustainable 11 refs 3 figs

intergenerational transfers and the social discount rate this paper investigates the relationship between intergenerational asset transfers and the choice of the discount rate for use in cost benefit analysis in a model of a competitive overlapping generations economy constrained by a socially managed exhaustible resource provided that there are no distortions in capital markets and that all agents hold perfect foresight cost benefit techniques will result in a pareto efficient resource allocation if the discount rate is set equal to the market rate of interest but since the path of the interest rate depends on the level of intergenerational transfers cost benefit techniques do not ensure a socially desirable distribution of welfare between generations a social optimum will result only if intergenerational transfers are properly chosen and enforced decentralized private altruism may result in intergenerational transfers that both present and future individuals would agree are too small if members of the present generation attach positive weight to the general welfare of future generations not simply their personal descendants in a world where intergenerational transfers are non optimal second best policy making may imply a constrained optimum that is inefficient together these findings suggest that cost benefit analysis is at best a partial criterion to policy formulation that should be used only in conjunction with ethical principles that define the proper distribution of welfare between present and future generations

the net national product and exhaustible resources the effects of foreign trade abstract it is the widely held view that estimates of national income should be corrected for the value of the extracted exhaustible resource stock this correction implies the counter intuitive result that the national income of an oil producer is unaffected by its vast oil reserves in this paper we review the definition of national income and discuss its relation to national welfare we show that an extra income should be imputed to the resource owning country based on the exportable resource stock part of the net adjustment for resource use is made to the income of the resource using and not the resource producing country

on the intergenerational allocation of natural resources it is known hartwick and others that under standard assumptions a society that invests in reproducible capital the competitive rents on its current extraction of exhaustible resources will enjoy a consumption stream constant in time it is shown here that this result can be interpreted as saying that an appropriately defined stock of capital including the initial endowment of resources is being maintained intact and that consumption can be interpreted as the interest on that patrimony this seems like a useful rule of thumb for policy

does nnp growth indicate welfare improvement abstract we show that instantaneous increases in real nnp over time are an accurate indicator of true dynamic welfare improvements this highlights a connection between the theory of green or comprehensive national income accounting and the theory of real price indices

one sided sustainability tests with amenities and changes in technology trade and population abstract if an economy with multiple consumption goods including environmental amenities uniquely maximises present value with constant discounting it is unsustainable at some time if either of two measures augmented net investment or the change in augmented green net national product are zero or negative then augmented denotes that time is treated as a productive stock which includes in each measure the value of future exogenous changes in technology or terms of trade adjustments are found to make each measure a test for individual sustainability when population grows exogenously the practical and philosophical rationale for testing sustainability in a present value maximising and therefore fully prescribed development path is discussed

national accounts and environmental resources in the paper optimal growth theory is used to derive the appropriate definition of the net national product concept when there are environmental resources and environmental damage to take into account the basic conclusions are that conventional defined np should be corrected by deducting environmental damage and adding the value of the net change of all resources

external ownership and innovation in the united kingdom this paper examines the impact of ownership and a variety of other variables on the likelihood of innovation and the presence of an r d function within a national sample of uk defence related firms it is shown that foreign ownership has a negative indirect impact upon innovation mixed support is found for the schumpeterian approach to innovation involvement in export markets technological opportunity and r d collaboration are shown to have a positive impact on innovation

technology strategy for enhancing the public to private technology transfer evidence from the duration of patent patents are typically characterized as assets of great values nevertheless there are many patents that are actually never used in this article we claim that there is a relationship between the duration of patents and the characteristics of the underlying invention from the viewpoint of public research institutes the duration of patents may be a proxy of probability of technology transfer because the long lived patents have higher value and more chances to be transferred we characterize the patents along different dimensions captured by the renewal and application data i e collaboration scope competitiveness and attractiveness the results of hazard rate duration analysis tell us that long lived patents are characterized by being more focused having more competitiveness and being more collaborative in addition it is analysed that patents in chemical industry expire faster than those in electrical electronic industry though this fact is against the general intuition it may be reasonable fro

an overlapping generations model of climate economy interactions a numerically calibrated overlapping generations model of climate change and the world economy is examined in this paper in the absence of intergenerational transfers efficient rates of greenhouse gas emissions abatement rise from 16 in the present to 25 in the long run while mean global temperature increases by 7 40c relative to the preindustrial norm a utilitarian optimum which attaches equal weight to each generation s life cycle utility yields abatement rates that rise from 48 to 89 with a long run temperature increase of 3 40c a second best utilitarian path in which intergenerational transfers are by assumption institutionally infeasible also supports stringent abatement measures i introduction the infinitely lived agent framework pioneered by frank ramsey 1928 has emerged as a central structure in the economics of climate change as characterized by ipcc 1996 working group iii climate change occurs when anthropogenic emissions of greenhouse gases principally carbon dioxide but also chlorofluorocarbons methane nitrous oxide and water vapor contribute to long term increases in mean global temperature potentially disrupting ecological systems and climate dependent production activities the best known study on the economics of this subject is nordhaus 1994 dynamic model of climate and the economy dice which incorporates assumptions regarding the costs and benefits of greenhouse gas emissions in a standard one sector growth model in nordhaus analysis a 50 reduction in greenhouse gas emissions would reduce gross world output by 0 93 a doubling of greenhouse gas concentrations relative to the preindustrial norm which is expected to occur by the middle of the twenty first century would reduce output by

measuringincome and measuring sustainability we examine what interpretation can be given to inclusive income understood to be consumption plus the value of the net increase in all relevant capital stocks we introduce the concept of instantaneously constant value income defined as the maximum amount the economy can consume at a moment of time and keep the expected present value of utility of current and future generations constant we argue that this income concept captures some of the concerns underlying sustainability our main result is that inclusive income equals instantaneously constant value income we show that this result holds in a very general setting and in particular carries over to models incorporating technological progress when such progress can be captured by augmented stocks of knowledge an important implication of our main result is that it provides a very simple method for deriving inclusive income which does not involve any linearization of the hamiltonian

natural resources national accounting and economic depreciation abstract the current value hamiltonian in an aggregate optimal growth problem with heterogeneous capital stocks including exhaustible renewable and environmental stocks is the nnp function routine substitutions reveal that the using up of natural resource stocks is representable as easy to interpret economic depreciation magnitudes we obtain true nnp inclusive of natural resource stock diminution implications for actual national accounting practices are also discussed

intergenerational altruism and the environment we construct an overlapping generations model of pollution externality in which individuals are altruistically linked to their offspring as in barro 1974 it is shown that steady state consumption may be a decreasing function of the intergenerational degree of altruism despite individuals altruism the competitive equilibrium is not optimal we thus study the social optimum and show that it can be decentralized

conservationist government policies and intergenerational equity in an overlapping generations model with renewable resources abstract this paper shows that in overlapping generations models incorporating renewable natural resources competition may lead to perpetually declining living standards in environments in which it is technically feasible to achieve intergenerationally equitable distributions of consumption first and second best conservationist government policies are examined these include forced nationalization of the entire stock of natural capital government open market purchases and sales of natural capital taxation of industrial use of resources and subsidies to private investments in natural capital

unemployment duration and individual heterogeneity a regional study this paper investigates the impact of individual heterogeneity and regional influences on unemployment duration utilizing cross section microeconomic data drawn from a representative random survey of individual job seekers for the english county of kent these individual level data are unique in that they provide information concerning the personal characteristics of job seekers alongside direct observations of both their reservation wages and job search behaviour such data are rare and to the authors knowledge have never before been utilized in a regional context thus the paper contributes to the empirical literature by analysing the extent to which individual heterogeneity and intra regional variation in labour market opportunities impact upon the observed distribution of unemployment duration s in particular the paper analyses the extent to which the duration of unemployment is determined by individual choice this is an important issue for the formation and evaluation of policy these result

an overlapping generations model of growth and the environment this article analyzes the potential conflict between economic growth and the maintenance of environmental quality in an overlapping generations model short lived individuals make decisions which have long lasting effects on both factor productivity and the environment the model provides a theoretical explanation of observed correlations between environmental quality and income whereby economic growth is associated first with declines then improvements in environmental quality it suggests circumstances in which multiple pareto ranked steady state equilibria may arise and in which sustained growth of both capital and environmental quality may occur overmaintenance of the environment analogous to dynamically inefficient overaccumulation of capital may emerge copyright 1994 by royal economic society

stopped in the name of the law administrative burden and its implications for cash transfer program effectiveness summary cash transfer programs have achieved wide ranging success in reducing poverty yet there is little empirical research on how program rules and administrative capacity might limit program effectiveness we examine administrative burden and quantify its implications for grant access and impacts in the south african child support grant csg program as the age of eligibility and application requirements changed over time we find that approximately 60 of the sampled children experienced an interruption or disconnection in cash transfer receipt and that both timing and dosage loss are associated with adolescent engagement in risky behaviors and for females lower educational attainment

sustainability constraints versus optimality versus intertemporal concern and axioms versus data sustainable sustained or survivable development are defined here as distinct sustainability constraints on intertemporal distribution in a context which ignores uncertainty environmental and intratemporal concerns such constraints are neither self contradictory nor redundant for they can conflict with maximizing the present value of utility optimality nor inferior since the axioms underlying optimality are ethically arbitrary and refuted by empirical psychological data axiomatic arguments may clarify but cannot resolve debates about intertemporal concerns data suggest that sustainability constraints are not respected and that intertemporal welfare functions containing a preference for sustained improvement may better reflect what bodies politic mean by sustainability

intergenerational resource rights efficiency and social optimality the discipline of economics is generally defined as the science of the allocation of scarce resources between competing social objectives given an initial distribution of resources between economic agents how would they behave so as to improve their welfare according to the pareto criterion the agents would exchange commodities until the opportunities for fruitful exchange were fully exhausted and no agent could be made better off without rendering at least one other agent worse off pareto efficiency is a powerful concept in microeconomic analysis provided that the initial distribution of property rights is equitable allocative efficiency gives rise to the best of all possible worlds acknowledging that the assumptions of perfect competition are often violated firms are monopolistic information is incomplete and externalities exist economists have argued for the modification of institutions so that economic reality will conform more closely to the assumptions of the model that yields such gratifying results but microeconomic theory has always maintained that allocative efficiency is in itself insufficient to maximize social welfare bator 1957 a social welfare function is required to discriminate a social optimum among the array of efficient allocations that correspond to alternative assignments of property rights though economists have posited alternative functional forms for the sake of pursuing conceptual arguments welfare functions have remained elusive constructs for well known theoretical and practical reasons consequently a sharp line of demarcation has been drawn between questions of efficiency the province of economics and equity the principal focus of ethical and political discourse in resource economics however the line demarcating efficiency and equity is often crossed the term optimal depletion appears regularly where only efficient depletion is meant while political debates about resource exploitation over time are laden with questions of the proper distribution of our natural patrimony between generations resource economists have predominantly espoused particular use rules that guarantee efficiency but overlook potential improvements in social welfare achievable through the reassignment of property rights across generations we document the evolution and current status of the misuse of the term optimal depletion in section ii we develop a simple two generation three period general equilibrium model in section iii to illustrate how alternative distributions of resource rights between generations relate to alternative pareto efficient solutions in section iv we demonstrate how different social welfare functions affect the optimal solution and associated assignment of resource rights between generations