an empirical model of job to job transition with self selectivity the statistical relationship between accepted job duration and the job to job transition strategy chosen by job quitters is analyzed using parametric duration methods because job quitters can sort themselves between unemployed and employed search the labor market state occupied before acceptance of a new job must contain information about the search preferred strategy the results show that jobs preceded by unemployment tend to be shorter but also reveal a substantial amount of heterogeneity when the sample is split between those having comparative advantages in unemployed search and those with comparative advantages in employed search however even for those who have comparative advantages in unemployed search choosing unemployment does not seem to raise subsequent job duration

cost benefit assessment of energy efficiency investments accounting for future resources savings and risks in the australian residential sector this article focuses on the impact of the discount rate on cost benefit assessment of investment options for residential building efficiency an integrated thermal modeling life cycle costing approach is applied to an extensive sample of dominant house designs for australian conditions the relative significance of predicted thermal performance and the applied discount rate on the present value of energy savings from alternative investment scenarios is investigated costs and benefits are also evaluated at the economy wide scale including carbon pricing considerations and for a test case household faced with alternative investment options at the point of construction the influence of the applied discount rate on produced cost benefit calculations is investigated as is the interaction between critical cost benefit input parameters findings support that the discounting framework is the primary driver of difference in estimates about costs and benefits of higher standards of efficiency in the residential sector results demonstrate that agreement on a low discount rate based on sustainability principals would prioritise those projects with significant environmental benefits

discounting in a world of limited growth this paper explores the consequences fordiscounting of assuming limits to growth one of the main determinants of the discount rate is the rate of economic growth if growth rates decline in the future then the discount rate should not be constant but also decline over time in fact we would then need not a single discount rate but rather a variable discount schedule this would imply higher present values for the distant future the paper analyses how discount rates would vary with different assumptions about the patterns of growth and the pure rate of time preference

on the pricing and benefit structure of a private club or public utility in this paper we have analyzed the pricing and benefit structure of a private club or public utility by means of a simple two period model we have analyzed the relationship of the two period charges and their responses to a change in the rate of interest we have also analyzed the pricing schemes under various objectives which include the equal payment the social gain and the public choice cases the two period pricing schemes under the special cases where no intertemporal borrowing or lending is allowed and where memberships are growing at an exogenous rate have also been analyzed in addition we have presented a multiperiod model with exogenous growth in memberships and with the consideration of inflation a schedule of fair access charges for this model has been derived it should be useful in many practical applications

sustainability limited substitutability and non constant social discount rates abstract the paper shows how limited substitutability in consumption between different classes of goods affects the magnitude and time development of social discount rates it decomposes the discount rates into an absolute growth and a relative growth or substitutability effect the paper relates between good and intertemporal substitutability to the notions of weak and strong sustainability it analyzes under which circumstances low as opposed to high between good substitutability increases the weights given to long run environmental services

reconciling sustainability and discounting in cost benefit analysis a methodological proposal abstract the incorporation of the intergenerational equity objective has rendered the traditional cost benefit analysis cba approach obsolete for the evaluation of projects presenting an important number of environmental externalities and for those whose impacts extend throughout a long period of time based on the assumption that applying a discount rate rewards current consumption and therefore that it is only possible to introduce a certain intergenerational equity in a cost benefit analysis in this work we propose an approach to discounting based on a different rationale for tangible and intangible effects we designed two indicators of environmental profitability a the intergenerational transfer amount ita which quantifies in monetary units what the current generation is willing to pass on future generations when an environmental restoration project is carried out and b the critical environmental rate cer measures the implicit environmental profitability these concepts were tested through an empirical case study pertaining to the assessment of an erosion control project in the southeast of spain the results yield traditional profitability indicators that are higher and probably closer to the real values set by the contemporary society the information provided by the environmental profitability indicators proposed renders more transparency to the quantification of the levels of intergenerational equity applied thereby facilitating the difficult reconciliation of the cba technique with the objective of sustainability

double co2 and beyond benefits costs and compensation abstract economic decisions over what action if any to take concerning the greenhouse effect tend to revolve around the social discount rate implicitly the debate concerns how to attribute intertemporal weights to welfare and implies a moral stance that is rarely given explicit recognition refocusing on the outcomes of current actions emphasises the role of compensation a conflict is apparent between the view that the current generation need be unconcerned over the loss or injury caused to future generations because they will benefit from advances in technology investments in both man made and natural capital and direct bequests and the requirement to avoid harming the innocent changes in units of welfare cannot be viewed as equivalent regardless of their direction in general doing harm is not cancelled out by doing good the result is a rejection of the potential compensation principle which underlies the current economic stance and a reconsideration of the acceptability of compensation altogether the concept of human rights and a non utilitarian perspective are used to show how cost benefit analysis denies the existence of inalienable rights and economics limits the moral considerability of harm

estimating a market equilibrium search model from panel data on individuals from albrecht and axell 1984 and is based on workers who are homogeneous in terms of market productivity and heterogeneous in terms of nonmarket productivity and on firms which are heterogeneous in terms of productive efficiency the equilibrium model is contrasted in terms of its fit to the data with an unrestricted version of the model which is based on a mixture of negative binomial distributions the equilibrium model fails to conform to the data in exactly the dimension of its major focus namely it implies that measurement error accounts for almost all of the dispersion in observed wages the equilibrium model also does not do well in fitting the unemployment duration distribution compared to the unrestricted model the problem is that the duration distribution itself does not support the existence of significant heterogeneity as evidenced by the estimates of the unrestricted model the paper also illustrates the use of such models for policy analysis by simulating the welfare effects of a minimum wage

the evolution of hyperbolic discounting implications for truly social valuation of the future abstract we explore the standard expected utility model and alternatives to it we then examine the behavioral and neurological evidence for hyperbolic discounting we discuss evidence related to the neurological and behavioral evolution of discounting in non human animals and in humans we explore new findings about the importance of sociality in human behavior and the implications for truly social time preference finally we discuss the implications of the neurological evidence on discounting for social environmental valuation in particular the implications for very long run decisions such as those involved in climate change mitigation and biodiversity preservation

calculating the welfare costs of import restrictions in the imperfect substitutes model this paper supplies equations for partial equilibrium calculations of the welfare effects of tariffs and quotas when the imported good and the competing domestic good are imperfect substitutes in demand the equations take into account the response of the price of the domestic substitute although other studies have acknowledged this response they have failed to account for it in their welfare calculations to demonstrate the importance of this response it is shown how it affects the calculations for the welfare costs of tariffs and quotas on us imports of footwear it is shown that ignoring the response of domestic prices leads to significant overstatement of the welfare costs of tariffs and significant understatement of the welfare costs of quotas for the industry

estimating a simultaneous search model the primary goal of this article is to specify and estimate a structural simultaneous search model and then determine the empirical importance of simultaneous search the results indicate that new labor force entrants search simultaneously a secondary goal is to identify and estimate job offer arrival rates and wage offer rejection probabilities separately the results indicate that a significant portion of unemployment spells are caused by slow arrival rates but policies intended to speed arrival rates would increase the average length of unemployment spells

a diagrammatic exposition of weak complementarity and the willig condition this article provides a graphical explanation for one of the most important restrictions to utility functions used in revealed preference approaches for measuring the demand for public goods and product quality weak complementarity it also describes how the willig condition is an important element along with weak complementarity in measuring hicksian consumer surplus for changes in public goods or quality using marshallian demand curves

harvest policies and nonmarket valuation in a predator prey system abstract although prey may not have commercial value their economic value can be ascertained in a predator prey model if the predator has a harvest value the economic optimal recovery path of the predator and prey are carefully described when growth is quadratic in the predator prey and linear in prey predator parameter values in part resembling pacific halibut are used to provide numerical illustrations

estimating the general equilibrium benefits of large changes in spatially delineated public goods the purpose of this article is to report a new approach for measuring the general equilibrium willingness to pay for large changes in spatially delineated public goods such as air quality we estimate the parameters of a locational equilibrium model and compute equilibria for alternative scenarios characterizing the availability of public goods within a system of communities welfare measures take into consideration the adjustments of households in equilibrium to nonmarginal changes in public goods the framework is used to analyze willingness to pay for reductions in ozone concentrations in southern california between 1990 and 1995

optimal stalling when bargaining this paper analyzes an alternating offer model of bargaining over the sale of an asset in a market such as that for housing in which another agent may come and compete for the right to strike a deal the analysis allows the buyer and seller to have possibly differing views as to how likely such a competition is hence the buyer and the seller disagree about their respective bargaining powers these views adjust to market realizations as the parties learn it is shown that there exists a unique subgame perfect equilibrium which can be explicitly constructed hence conditional on market conditions equilibrium prices and optimal stall lengths that is delay can be found bargaining delay can only occur if there is optimism not pessimism and only if the parties are open to learning as time elapses this delay can occur even for very small levels of optimism and the delay can be for economically significant periods

unemployment insurance and male unemployment duration in canada a model of unemployment duration is estimated with weekly micro data on canadian men entitlement provisions in the unemployment insurance program and demand conditions are found to have a significant effect on the probability of leaving unemployment the probability of a worker leaving unemployment declines with the duration of unemployment holding unemployment insurance entitlement constant when entitlement is allowed to vary the probability of leaving first falls and then generally rises with unemployment duration these results are robust with respect to allowing for person specific unobserved heterogeneity and alternative specifications of duration dependence

equity and time to sale in the real estate market evidence from the boston condominium market of the early 1990s reveals that an owner s equity position determines his experience as a seller an owner of a property with a high loan to value ratio sets a higher asking price has a higher expected time on the market and if he sells receives a higher price than an owner with proportionately less debt the down payment requirement for purchasers but not incumbent owners provides a simple explanation for this phenomenon among owner occupants the results provide supporting evidence for equity based aggregate theories of price volume movements in the housing market copyright 1997 by american economic association

participation rules for pareto optimal clubs abstract this paper presents a unifying framework for the club participation problem using compensating variation measures of willingness to pay for membership with more prospective club members than the equilibrium club population pareto efficient participation rules are derived which depend upon whether or not individuals are assured of club access sale of lottery tickets offering club membership is shown to be a socially superior club participation allocation mechanism to sale of vouchers guaranteeing membership the willingness to pay format readily encompasses the buchanan case where all prospective club members are assured of club participation

natural resource economics and conservation contributions of agricultural economics and agricultural economists research by agricultural economists on natural resources has been distinguished by an interdisciplinary emphasis and a dynamic perspective it has recognized technological and institutional constraints has been oriented toward solving concrete resource management and policy problems and has emphasized empirical and quantitative analysis agricultural economists have introduced methods for evaluating natural resource conservation efforts for predicting adoption of resource conservation technologies and for designing efficient and sustainable resource management policies they have identified ways of improving land management and preventing land degradation proposed reforms of institutions governing water allocation and water quality and introduced policies for balancing environmental and efficiency considerations in the management of pests biodiversity and livestock diseases their research has had substantial impacts on the formulation of resource conservation policies

krutilla s legacy twenty first century challenges for environmental economics we all need heroes in academic life their ideas capture our imaginations convincing us that a set of problems is important often they are role models and mentors to young scholars certainly the academic enterprise would be less exciting and less productive without them this past year environmental economics lost john krutilla one of its founding fathers and a person i have always regarded as an academic hero few people have influenced environmental economics more than john it has now been fifteen years since his last major book was published bowes and krutilla and nearly forty years since the article conservation reconsidered that most environmental economists associate with him appeared in the aer a short recognition of his work prepared by resources for the future includes a comment by nobel laureate robert solow that captures the impact of this paper he observed that

the new approach to wilderness preservation through benefit cost analysis over the last 15 years economists of resources for the future led by john krutilla have been developing a new approach to wilderness preservation this paper offers a concise exposition of their approach and adds a few new steps the basic ingredient of the new approach is a perception of declining net benefits of wilderness development and rising net benefits of wilderness preservation over time these alter the entire shape of the benefit cost analysis of potential development the new steps involve reversibility postponability and recognition of multiple interest rates

an equilibrium model of search unemployment this paper develops a simple general equilibrium model with sequential search in which a nondegenerate wage offer distribution is endogenously determined we use this model to analyze the comparati

evaluation of nonmarket goods recovering unconditional preferences a new approach is proposed for the evaluation of nonmarket goods starting from a complete or incomplete conditional demand system for market goods which is observable and depends on nonmarket goods this information is not sufficient to recover the underlying preference ordering of the representative consumer the central idea is to employ additional marginal willingness to pay functions for the nonmarket goods since they can be estimated either together with the demand system or in a separate step they are less arbitrary than the assumptions or hypotheses usually made if the entire system is weakly integrable the underlying ordering and appropriate welfare measures can be derived in this article i investigate the relationship between conditional and unconditional demand systems present sufficient conditions for weak integrability and demonstrate the practicability of the procedure proposed by means of three examples

loss aversion in a consumption savings model abstract we propose a model of consumption and saving based on kahneman and tversky s prospect theory that implies a fundamental asymmetry in consumption behavior inconsistent with other models of consumption when there is sufficient income uncertainty a person resists lowering consumption in response to bad news about future income this resistance is greater than the resistance to increasing consumption in response to good news we present empirical evidence from five countries that confirms this behavior

the alberta dilemma optimal sharing of a water resource by an agricultural and an oil sector we fully characterize the optimal time paths of production and water usage by an agricultural and an oil sector that share a limited water resource we show that for any given water stock if the oil stock is sufficiently large it will become optimal to have a phase during which the agricultural sector is inactive followed by a phase during which both sectors are active again the agricultural sector will always be active in the end as the oil stock is depleted if agriculture is not constrained by the given natural inflow of water then oil extraction will always end with a phase during which oil production follows a pure hotelling path otherwise oil production never follows a pure hotelling path because its full marginal cost must always reflect not only the imputed rent on the finite oil stock but also the positive opportunity cost of water usage the case of oil and agriculture sharing a water resource is but one example our analysis provides a framework to generalize the hotelling rule to other cases where the full marginal opportunity cost of extracting a nonrenewable resource depends on the endogenous activity of some other sector of the economy

discounting of long term costs what would future generations prefer us to do decisions with intergenerational consequences may leave future generations worse off i e not be pareto optimal if costs and benefits are not discounted correctly we point out that this happens if the conventional social discount rate is applied to intergenerational costs with that rate the justification of intergenerational costs benefits of a project are invested and the proceeds can cover future costs leads to an inconsistency over the long term eventually the supposed benefits of any project become larger than the entire gnp the conventional approach commits an error by treating the time preference component of the discount rate as if it represented creation of wealth while it really involves only redistribution the time horizon of the redistribution is limited by the duration of market transactions especially loans thus we recommend a two step discounting procedure with the conventional social discount rate for the short term about 30 years and the growth rate of the economy for the long term data for gnp per capita growth in the us the uk france germany japan and the soviet union since the industrial revolution combined with data for net economic welfare per capita suggest an intergenerational discount rate in the range of 1 to 2 for practical application the rate at which costs and benefits will grow over time is just as important as the discount rate only the difference between these two rates matters for many environmental costs these rates may be close to each other during the next few generations this implies that some of the uncertainty in the prediction of rates cancels and one can treat the problem as if the effective rate were close to zero the consequence for costs such as global warming or nuclear power can be very significant the valuation can increase by more than an order of magnitude compared to values based on conventional discounting

inducing patterns of correlation and substitution in repeated logit models of recreation demand repeated logit models are among the most commonly applied methods for modeling seasonal recreation demand in this article we examine the capabilities of the repeated nested logit and repeated mixed logit models to capture patterns of error correlation and demand substitution particular attention is paid to the use of the mixed logit framework to generalize the strong assumptions on correlation patterns across sites and choice occasions imbedded in the nested logit model we examine the implications for the range of price elasticities allowed in both models based on the implied correlation structures copyright 2002 oxford university press

a bio economic model of community incentives for wildlife management under campfire this paper formulates a bio economic model to analyze community incentives for wildlife management under benefit sharing programs like the communal areas management programme for indigenous resources campfire in zimbabwe three agents influence the wildlife stock a parks agency determines hunting quotas outside poachers hunt illegally and a local community may choose to protect wildlife by discouraging poaching wildlife generates revenues from hunting licenses and tourism it also intrudes on local agriculture we consider two benefit sharing regimes shares of wildlife tourism rents and shares of hunting licenses resource sharing does not necessarily improve community welfare or incentives for wildlife conservation results depend on the exact design of the benefit shares the size of the benefits compared with agricultural losses and the way in which the parks agency manages hunting quotas

what is the role of the asking price for a house abstract this paper considers the role of the asking price in housing transactions both theoretically and empirically significant fractions of housing transactions involve sales prices that are either below or above asking price which might suggest that asking price has limited relevance however many housing transactions involve a sales price exactly equal to asking price a fact that has previously drawn little notice strongly suggesting that asking price does matter the paper develops a model where asking price is neither a binding commitment nor a ceiling yet still directs buyer search and impacts sales price using novel survey data the paper provides empirical evidence consistent with asking price playing a directing role in buyer search consistent with theory this effect is stronger for more atypical houses and in bust markets

why the far distant future should be discounted at its lowest possible rate abstract a critical feature of the distant future is currently unresolvable uncertainty about what will then be the appropriate rate of return on capital to use for discounting this paper shows that there is a well defined sense in which the lowest possible interest rate should be used for discounting the far distant future part of any investment project some implications are discussed for evaluating long term environmental projects or activities like measures to mitigate the possible effects of global climate change

on the environmental discount rate abstract in this paper i show that environmentalism itself can provide a rigorous foundation for the low and declining discount rates that environmentalists seem to favor in long term cost benefit calculations if indeed it is a stylized fact that we are moving toward a world where environmental spending is increasingly important that scenario per se may significantly lower the social rate of return a formula is derived for the ratio of social to private discount rates as a simple function of two operational environmental parameters the formula is used to explain why the social rate of return ought to be lower than the private rate and why this gap called environmental drag when measured in terms of equivalent evaporation of national income may be expected to increase over time

the substantial bias from ignoring general equilibrium effects in estimating excess burden and a practical solution we show that under typical conditions the simple excess burden triangle formula substantially underestimates the excess burden of commodity taxes in some cases by a factor of 10 or more this formula performs poorly because it ignores general equilibrium interactions most important interactions between the taxed commodity and the labor market many prior studies have shown that general equilibrium interactions affect excess burden but have not appreciated the bias associated with ignoring these interactions or the quantitative importance of this bias we derive an implementable alternative to the simple formula this alternative formula captures interactions that the simple formula omits as a result it is both unbiased and usually more accurate

capital investment for optimal exploitation of renewable resource stocks in the age of global change abstract the world is rapidly changing and biotic resources and their users are adapting determining how ecological and economic interactions determine the outcomes of this adaptation is critical to understanding the future of natural resources we model a two species fisheries as a stylized system to investigate the adaptation strategies of a harvester faced with shifting species composition in an ecological community we explore how interspecies interactions and pricing effects jointly determine the optimal adaptation strategy we consider two interacting species that are harvested jointly but where the harvester may exert effort towards each species differentially provided she invests in reproducible capital that allows targeting the possible adaptation strategies comprise changes in how people interact with natural capital for example changing harvest levels and investment in reproducible or human capital which may be a substitute or complement for natural capital stocks we find that the market price of the harvested species exerts a particularly strong impact on the adaptation strategy all else equal unequal prices tends to drive extreme targeting or avoidance of a new species economic and ecological factors can necessitate investment at equilibrium and early transient management decisions for beneficial species may like with nuisance species produce large benefits

what s the use welfare estimates from revealed preference models when weak complementarity does not hold abstract in this paper we consider the theoretical and empirical ramifications of welfare measurement in revealed preference models when weak complementarity does not hold in the context of a kuhn tucker model of recreation demand we show that while it is possible to estimate preferences that do not appear to exhibit weak complementarity the calculation of welfare measurements from these models requires a cardinal interpretation of preferences that cannot be tested furthermore we reiterate the under appreciated fact that even traditional use value estimates require a cardinal restriction on preferences that while often intuitive also cannot be tested we demonstrate empirically that the choice of restrictions can have significant ramifications as use value estimates can vary based on the assumed preference structure

the economics of climate change and the theory of discounting this paper confronts the theory of discounting with climate change economics standard discounting would give long term damages a very low present value on the other hand low discount rates would imply more sacrifices for present generations although future generations may be richer and using multiple rates would lead to economic inefficiencies the paper first shows that arguments favouring a low or zero discount rate in general are weak even from an ethical point of view it goes on by considering different arguments in favour of discount rates decreasing over time and by recalling the argument that non reproducible environmental assets should be given a value growing over time through the example of climate change it finally shows that the latter argument not only implies that the costs of damages associated to climate change should not be underestimated but also reinforce the legitimacy of using decreasing discount rates

selling a lemon under demand uncertainty we consider a seller who has private information about the quality of her good but is uncertain about buyer arrivals assuming that the high quality seller insists on a price we show that the low quality seller s surplus and pricing strategy crucially depend on buyers knowledge about the demand state if they are also uncertain about demand then demand uncertainty increases the low quality seller s expected payoff and her optimal strategy is to lower the price after some time if buyers know the demand state then demand uncertainty does not affect the low quality seller s payoff but she must employ a sophisticated pricing strategy

reassessing the government s discount rate policy in light of new theory and data in a world economy with a high degree of capital mobility abstract the paper reexamines the government s discount rate policy in the context of new evidence on international capital mobility the relationship between deficits and interest rates the relationship between consumer interest rates and the consumer s rate of time preference and intergenerational compensation it concludes that the approximate discount rate for government decisions will differ depending on the policy problem and that the government s borrowing rate is appropriate in some cases and in others the private rate should be used for long term policies the benefit cost rationale for discounting breaks down and must be reestablished on principles incorporating intergenerational equity

exploration and exhaustible resources the microfoundations of aggregate models the appropriate specifications for aggregate extraction and exploration cost functions are derived from a disaggregate model of the search for low cost deposits of an exhaustible resource the common practice of combining the no discovery extraction cost function with exploration is shown to result in a misspecified model for which the total cost of extracting the resource is not well defined the widely accepted prediction that the anticipated discovery of low cost deposits results in a u shaped price path appears to be an artifact of this misspecification for the authors properly specified cost functions the predicted resource price always rises copyright 1989 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

regional employment impacts of marine energy in the scottish economy a general equilibrium approach gilmartin m and allan g regional employment impacts of marine energy in the scottish economy a general equilibrium approach regional studies one aspect of the case for policy support for renewable energy developments is the wider economic benefits that are expected to be generated within scotland as with other regions of the uk there is a focus on encouraging domestically based renewable technologies this paper uses a regional computable general equilibrium framework to model the impact on the scottish economy of expenditures relating to marine energy installations the results illustrate the potential for considerable legacy effects after expenditures cease in identifying the specific sectoral expenditures with the largest impact on lifetime regional employment this approach offers important policy guidance

measuring trade creation and trade diversion in the central american common market a hicksian alternative abstract a large number of empirical studies on customs union formation or economic integration base their evaluation of the welfare implications of regional integration schemes on trade creation and trade diversion measures that are derived from an ordinary marshallian import demand curve this approach is however influenced by the path dependence problem which affects the reliability of the estimated results this paper derives alternative hicksian measures of trade creation and trade diversion using the popular notions of compensating and equivalent variation these notions allow for more exact estimation of the welfare impact since they incorporate the path independence condition these new measures are applied to the integration effort in the central american common market cacm the overall results show that economic integration in central america has been largely trade diverting for the selected commodity groups

do open access conditions affect the valuation of an externality estimating the welfare effects of mangrove fishery linkages in thailand mangroves are considered ecologicallyimportant due to their role as breedinggrounds and nursery habitats for off shorefisheries however mangrove deforestationthrough conversion to shrimp aquaculturethreatens this valuable function this paperdevelops a dynamic production functionapproach to analyze the influence of habitatchanges on an open access fishery that faces afinite elasticity of demand the basic modelis applied to a case study of the impacts ofmangrove deforestation on the artisanal marinedemersal and shellfish fisheries in thailand by estimating parameters through pooledtime series and cross sectional data over the1983 1993 period for the five coastal zones ofsouthern thailand the welfare impacts ofmangrove deforestation are estimated underdifferent elasticity of demand assumptions under pure open access the welfare lossesestimated for mangrove deforestation inthailand of 30 km2 annually ranged from 12 000 to 408 000 depending on theelasticity of demand

a theory of intergenerational clubs intertemporal pareto efficient conditions for provision and maintenance of the shared good tolls membership size and financing are presented for intergenerational clubs an optimal membership span is also determined for nonlifetime members these pareto efficient conditions account for atemporal crowding intertemporal depreciation due to utilization and the sequence of members adequate incentives exist for privately owned clubs to act with foresight but do not necessarily exist for government owned clubs nevertheless privately owned clubs must be operated by a firm rather than the members if free rider problems regarding maintenance are to be avoided

optimal harvesting of ecologically interdependent fish species abstract the optimal exploitation of a two species predator prey system is considered using lotka volterra type equations due to the density dependence of ecological efficiency both species should be harvested simultaneously over a range of relative prices beyond the limits of this price range either the prey species should be utilized indirectly by harvesting the predator or the predator should be eliminated to maximize the prey yield neglecting harvesting costs the simultaneous harvest of prey and predators requires that a unit of prey biomass increase in value by being processed by predators certain results from single species fishery models are shown not to apply to multispecies models these are as follows i optimal regulation of a free access fishery may call for subsidizing instead of taxing the harvest of predator species ii increasing the discount rate may at moderate levels imply that the optimal standing stock of biomass increases instead of decreasing iii a rising price or a falling cost per unit fishing effort of a species may raise and not lower the optimal standing stock of that species

property rights and natural resource conservation a bio economic model with numerical illustrations from the serengeti mara ecosystem this study develops a model for wildlifemigrating seasonally between a conservationarea and a neighbouring area when beingoutside the conservation area harvesting takesplace by a group of small scale farmers thelocal people have two motives for harvesting to get rid of problem animals as roamingwildlife destroys crops and agriculturalproducts and hunting for meat and trophies depending on the specification of the propertyrights the harvesting is legal or illegal itis demonstrated that it is far from clear whichof the two property rights regimes that givesthe highest wildlife abundance hence contraryto what is argued for in the literature handing the property rights over to the localpeople means not automatically more wildlifeand a more sustainable resource utilization the reason lies in the nuisance motive forharvesting the exploitation under the twodifferent property rights regimes areillustrated by numerical calculations with datathat fits reasonable well with the exploitationof the wildebeest population in theserengeti mara ecosystem

housing price bubbles new supply and within city dynamics abstract although there is broad recognition that cities differ in their tendency to experience house price bubbles most studies assume away any possibility of within city heterogeneity in response to a bubble we develop a model that suggests that this assumption may be appropriate when markets are rising but can be far from reality on the bust side of a bubble during a housing boom new construction and related supply adjustments by developers ensure stable relative prices between low and high quality segments of the housing market on the bust side of a bubble however reduced housing starts allow demand side forces and mortgage default to create pressure for relative prices to diverge across market segments absent a change in technology as markets recover and new construction rebounds relative prices should revert back to pre crash levels evidence based on 2000 2013 single family home sales in phoenix arizona supports this modeling framework additional evidence also suggests that high rates of mortgage default contributed to divergence in relative prices when markets crashed

recovering weakly complementary preferences abstract this paper demonstrates a method for recovering weakly complementary expenditure and indirect utility functions while integrating back from marshallian demand specifications that do not intrinsically embody weak complementarity weak complementarity of a good with quality provides information about how the constant of integration over price must behave with respect to quality and this information can be incorporated into the process of recovering preferences the weakly complementary expenditure and indirect utility functions are recovered for the linear demand specification and for the stone geary utility function with any value of the subsistence parameter

the macroeconomics of dr strangelove the cold war has ended and president george bush has declared the beginning of a 4 new world order this new world order has so far been characterized by the intensification of regional disputes civil strife and civil war its implications for arms proliferation and arms control are still unclear this paper considers both superpower conflict and the transition to international cooperation in the context of a model that emphasizes intergenerational linkages specifically we explore the weapons accumulation decisions of two adversarial countries in the context of a deterrence conflict initiation game embedded in an overlapping generations model the demographic structure of the overlapping generations model allows the analysis of both between and withincountry intergenerational external effects caused by past weapons accumulation decisions while the two country setting permits consideration of international external effects caused by the adversary country s current weapons accumulation decision we analyze the noncooperative equilibrium and then consider the effects of a regime change characterized by international cooperation but where the intergenerational externali

the role of the list price in housing markets theory and an econometric model summary houses are routinely sold at prices below but rarely sold at prices above their list prices list prices appear to be price ceilings that preclude the possibility of sales at higher prices this paper presents a theory of sellers behaviour that explains why there are list prices in housing markets and why list prices are distinct from sellers reservation prices the theory forms the basis of an econometric model that has been estimated using data from the baltimore md area the estimated model predicts sale and reservation prices conditional on list prices the predictions of sale prices are considerably more accurate than those obtained from a standard hedonic price regression the estimated model also explains why sellers may not be willing to reduce their list prices even after their houses have remained unsold for long periods of time houses are routinely sold at prices below and are virtually never sold at prices above their list prices the list price of a house appears to be a price ceiling that precludes the possibility of selling at a higher price this phenomenon is stable over time so it is not caused by market disequilibrium what is the role of list prices in housing markets can list prices be used to predict sellers reservation prices can they be used to make predictions of sale prices that are more accurate than predictions obtained from standard hedonic regressions this paper develops an econometric model of the behaviour of sellers in housing markets that answers these questions the model explains why there are list prices in housing markets and how sellers establish list and reservation prices in addition the model predicts sale and reservation prices conditional on list prices the predictions of sale prices are considerably more accurate than those obtained from a hedonic price regression the model also explains why sellers may not be willing to reduce their list prices even after their houses have remained unsold for long periods of time there have been several previous attempts to model the formation of list prices in housing markets guasch and marshall 1985 and stull 1978 developed search models in which list prices must be set but these models do not admit the possibility that sale prices may bse below list prices chinloy 1980 developed a model in which the seller s reservation price is assumed to be a constant fraction of the list price but chinloy did not explain why list and reservation prices are distinct or why they are proportional to one another these difficulties are not present in the model developed in this paper the theory underlying the model is developed in section 2 the model is presented in section 3 estimation results and some applications are given in section 4 additional applications are given in section 5 and concluding comments are given in section 6

an empirical stationary equilibrium search model of the housing market this article specifies and estimates a computationally tractable stationary equilibrium model of the housing market the model is rich and incorporates many of its unique features buyers and sellers simultaneous search behavior heterogeneity in their motivation to trade transaction costs a trading mechanism with posting prices and bargaining and the availability of an exogenous advertising technology that induces endogenous matching estimation uses maximum likelihood methods and multiple listing services data the estimated model is used to simulate housing market outcomes when a the amount of information displayed on housing listings increases and b real estate agent s commission rates change

matching turnover and unemployment this paper develops the view that workers move into and out of the labor market because of changes in the perceived value of their market opportunities a search model is combined with a matching model to yield movement of workers from job to job and into and out of employment

valuing the environment as input review of applications to mangrove fishery linkages the following paper reviews recent developments in the methodology for valuing the role of wetlands in supporting economic activity the main focus will be on mangroves serving as a breeding ground and nursery habitat in support of coastal and marine fisheries as this particular ecological function of a mangrove system means that it is effectively an unpriced environmental input into fisheries then it is possible to value this contribution through applying the production function approach the first half of the paper overviews the procedure for valuing the environment as an input applied to the case of a wetland supporting a fishery both the static ellis fisher freeman approach and the dynamic approach developed by barbier and strand incorporating the intertemporal bioeconomic fishing problem are reviewed the second half of the paper discusses briefly two recent case studies of mangrove fishery valuation an application in south thailand which is based on the static ellis fisher freeman model and an application in campeche mexico which is based on the dynamic approach 2000 elsevier science b v all rights reserved

competitive pricing and efficiency in search equilibrium we consolidate and generalize some results on price determination and efficiency in search equilibrium extending models by rubinstein and wolinsky and by gale heterogeneous buyers and sellers meet according to a general matching technology and prices are determined by a general bargaining condition when the discount rate r and search costs converge to 0 we show that prices in all exchanges are the same and equal the competitive market clearing price given positive search costs efficiency obtains iff bargaining satisfies hosios condition and r 0 when prices are set by third party market makers however we show that search equilibrium is necessarily efficient

optimal land conversion and growth with uncertain biodiversity costs abstract the aim of this paper is to characterise the trade offs between economic growth and natural resource conservation by determining the optimal rate of conversion of a natural reserve of land land conversion fuels consumption growth in the private sector while simultaneously giving rise to uncertain environmental consequences accounted for in terms of biodiversity benefits and modelled as non linear stochastic processes random processes governing ecosystem dynamics and adaptation to anthropogenic change are important sources of prevailing ecological uncertainty and contribute to the problem of how to balance economic development against natural resource conservation in a two sector exogenous growth framework we model a stochastic environmental good exhibiting uncertain ecological responses to environmental change and describe the economic and environmental trade offs facing a risk averse social planner allowing for ecological risk tends to slow economic growth if environmental impacts are assumed to increase exponentially as the rate of disturbance increases taken in isolation the effects of ecosystem resilience and ecological uncertainty on the rate of natural resource development are ambiguous and depend on normative parameters such as the social planner s attitude to risk and rate of time preference

depletion of the environmental basis for renewable resources the economics of interdependent renewable and nonrenewable resources abstract this paper synthesizes familiar theories of nonrenewable and renewable resource economics in a two sector partial equilibrium analysis of efficient trade offs between renewable resource production and environmental development the irreversible impacts of coastal zone development provide a motivating example while development proceeds the efficient harvest of renewable resources may exceed the sustainable rate while development may involve several periods of growth and decline once development begins it proceeds without significant interruptions if a profitable renewable sector survives development ceases before exhausting all profitable opportunities interdependent stocks reduce distinctions between resource types because each sector exhibits features of the other

stigma effects of nonemployment i introduction it is well known that longer durations of past nonemployment are associated with longer durations of future nonemployment 1 two explanations have been offered in the literature to interpret this phenomenon heterogeneity and the effect of workers employment histories the heterogeneity explanation argues that individuals differ in certain observed and unobserved characteristics and that these differences affect the duration of their periods of nonemployment however these individuals are unaffected by the mere experience of nonemployment because individuals with longer spells of nonemployment in the past are more likely to have characteristics that make them remain nonemployed they are likely to experience longer spells of nonemployment than others in the future the work history explanation argues that the mere experience of longer spells of nonemployment in the past raises the chance of longer spells of nonemployment in the future two theoretical explanations have been offered to explain this structural relationship human capital decay and stigma human capital decay suggests that nonemployed workers lose vital work experience and on the job training or suffer from human capital decay that reduces their future employability stigma suggests that potential employers infer the unobserved components of the workers quality from their history of employment and nonemployment in particular past nonemployment sends a negative signal to potential employers that lowers the probability of future reemployment 2 the ability to distinguish between heterogeneity and the effect of work history is a crucially important policy issue if the observed correlation between the duration of successive nonemployment spells reflects heterogeneity across individuals then a given individual enjoys the same chance of reemployment no matter how long or short his periods of past nonemployment have been in this case chronic nonemployment is a problem of a population subgroup and traditional training programs targeted toward the chronically nonemployed would be an appropriate policy tool moreover the programs could be targeted at individuals with the characteristics associated with a high risk of chronic nonemployment however if the observed correlation reflects the effect of work history anyone who happens to have experienced long periods of nonemployment in the past has a high probability of experiencing long periods of nonemployment in the future thus phelps 1972 argues that short term macroeconomic policies that alleviate unemployment will also lower aggregate unemployment rates in the long run 3 i argue however that an appropriate policy depends on the cause of the work history effect if the effect reflects human capital decay then short term macroeconomic policies to alleviate unemployment and traditional government training programs to help the unemployed restore lost skills are appropriate if the effect reflects stigma active short term macroeconomic policies may not be necessary to lower aggregate unemployment rates in the long run because stigma effects are likely to be weaker when nonemployment is experienced during a severe recession than when it is experienced during a moderate recession an appropriate policy would aim at aiding the flow of accurate information on the quality of stigmatized workers in the private sector for instance the government might subsidize potential private sector employers costs of screening job applicants who established poor work histories during a period of moderate recession alternatively it might sponsor private sector internship and training programs for such workers 4 although both the duration and frequency of nonemployment determine the individual s nonemployment rate the duration is empirically far more important than the frequency 5 because an understanding of the determinants of the duration of nonemployment is crucial to both economic theory and policymaking an enormous number of empirical studies have addressed the issue

financial subsidies to the australian fossil fuel industry abstract a common claim during international greenhouse gas reduction negotiations has been that domestic emissions cuts will harm national economies this argument fails to consider the distorting effect of existing financial subsidies and associated incentives to fossil fuel production and consumption provided by governments in most developed countries these subsidies support a fossil fuel energy sector that is the major contributor to global greenhouse gas emissions and conflict with attempts to expand the role of sustainable energy technologies reform of these types of subsidies has the potential to provide substantial gains in economic efficiency as well as reductions in carbon dioxide emissions a no regrets outcome for the economy and the environment this paper examines financial subsidies to fossil fuel production and consumption in australia and estimates the magnitude of the subsidies subsidies and associated incentives to fossil fuel production and consumption in australia are similar to those in the united states and the other countries that have pushed for increased flexibility during international negotiations

managing the international commons resource use and pollution control the simultaneous management in an international context of free access renewable resources and transboundary pollution is examined in a dynamic game framework first best outcomes under international cooperation are determined and compared to noncooperative outcomes when countries follow linear markov strategies an international policy consisting of taxes on emissions and harvesting with international redistribution of tax receipts is used to achieve the cooperative solution in addition side payments may be required to prevent free riding and thus make the international policy implementable

optimal exploitation and enhancement of environmental resources abstract this work is an analysis of the problem of the optimal utilization of environmental resources where both the renewable resource exploitation problem and the pollution control problem are placed in a general context of exploitation and enhancement of environmental resources the contribution of this work is to clarify the conditions for the existence of an optimal trajectory for the stationary environmental resource stock in terms of the functional forms of environmental enhancement activities and the indigenous growth rate function of environmental resources also three new economic insights gained from the analysis are presented

cooperation in an overlapping generations experiment abstract recent theoretical work shows that folk theorems can be developed for infinite overlapping generations games cooperation in such games can be sustained as a nash equilibrium but of course there are other equilibria this paper investigates experimentally whether cooperation actually occurs in a simple overlapping generations game subjects both play the game and formulate strategies our main finding is that subjects fail to exploit the intertemporal structure of the game even when we provided subjects with a recommendation to play the grim trigger strategy most of the subjects still employed safe history independent strategies journal of economic literature classification numbers c72 c92 d90

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

economic demand for marinas and projected impact on wetlands in 1982 there were over 9 million registered recreational boats in the u s nmma 1983 1 of this total 5 3 percent were registered in florida where there is one registered boat for every 22 florida residents the demand for boating and associated recreation both in florida and the nation has created a derived demand for marinas yet little is known about the theoretical and empirical aspects of the demand for marina services 2 furthermore marinas boating and all other forms of development and use place demands on the coastline and the shoreline of each state s navigable lakes rivers and streams the survival and development of the marina industry is in part dependent upon submerged land use submerged lands provide various environmental services or functions which may be reduced by marina development this is generally known as the wetlands issue which has led to legislation making marina development more difficult 3 the purpose of this article is to develop a theoretical framework for marina demand and

the home selling problem theory and evidence this paper formulates and solves the problem of a homeowner who wants to sell their house for the maximum possible price net of transactions costs including real estate commissions the optimal selling strategy consists of an initial list price with subs equent weekly decisions on how much to adjust the list price until the home is sold or withdrawn from the market the solution also yields a sequence of reservation prices that determine whether the homeowner should accept bids from potential buyers who arrive stochastically over time with an expected arrival rate that is a decreasing function of the list price this model was developed to provide a theoretical explanation for list price dynamics and bargaining behavior observed for a sample of homeowners in england in a new data set introduced by

considering aquacultural externality in coastal land allocation decisions in india commercial aquaculture in india has come under attack for having caused negative agricultural and environmental impacts this paper formulates an interactive model of non renewable and renewable resources to characterize land allocations between aquaculture and agriculture in ecologically and economically sustainable fashion through an empirical application various economic and policy circumstances that affect the optimal land allocation mix are evaluated the aquaculture industry must address two economic effects off site negative effects on renewable food and other coastal resources and on site self pollution of shrimp ponds current regulatory and land use policies are inadequate to address these effects

job matching and occupational choice this paper presents a model of job matching the generalizes the existing literature by allowing for different jobs types or occupations such differences affect the value of job specific experience inducing a career profile where certain types are sampled before others more specifically the analysis shows that it is optimal for the young and inexperienced to gravitate toward jobs exhibiting a certain kind of risk then after deriving the equilibrium job turnover rate for an economy in which people do not switch occupations panel data are used to estimate its underlying parameters the hypothesis that people do not switch occupations is rejected against the alternative that they do thus providing empirical support for the theoretical extension undertaken here