renewable natural resource management and use without markets natural resources by their nature are not readily bent to the status of private property efficient resource use is complicated by jurisdictional externalities public goods non use values and beneficiaries spatially separated from the location of resources the task is made more challenging by ecological complexity that obscures cause benefits and effects costs and dramatic time lags between individual actions and subsequent social consequences that together with substantial uncertainty introduce the chance of irreversibilities resource economists have played a major role in the literature on externalities the development of individual transferable quotas non market valuation techniques and common property management

state dependence and heterogeneity in fishing location choice to explore the distinction between state dependence and heterogeneity in repeated decisions this paper combines a mixed logit model with a state dependence parameterization from the marketing literature to study fishing location choices of commercial sea urchin divers in california it examines implications of ignoring either effect and finds in all cases that true state dependence is an important determinant of location choice consequently spatial policies like marine reserves can lead to differences in the short and long run behavioral responses of the fishing fleet under some specifications random preference parameters are statistically significant when state dependence is excluded from the model but when it is included random preference parameters are not significant in other specifications including state dependence only dampens the variability in preference parameters these results highlight the importance of gathering and analyzing diary type data for commercial fisheries as well as for similar choice problems in recreation demand

renewable resource economists and policy what differences have we made abstract this paper surveys developments in fisheries economics and fisheries policy over the past half century early work clarified the nature of the economic issues associated with open access laying the groundwork for changes in policies after coastal nations expanded their jurisdictions in 1976 perhaps the most important point made by economists is that property rights matter and that open access conditions create economic as well as biological problems the policy process has begun to create property rights systems although many of the world s fisheries still operate under mixed systems of regulations and open access incentives

what has and has not been learned about monetary policy in a low inflation environment a review of the 2000s as the world economy recovers from the worst financial crisis and most severe global slump in 75 years policymakers regulators and academics are focusing intensely and appropriately on lessons to be learned for monetary policy there are certainly many questions to answer among the most important are are inflation expectations well anchored what if any influence should asset quantities and prices have on monetary policy do we have sufficient confidence in our alternative monetary policy tools to stabilize the economy at the zero lower bound

the role of spatial scale in the timing of uncertain environmental policy the spatial scale of an environmental problem is dictated by boundaries physical boundaries limit the extent of impacts while the scale of decision making creates perceived boundaries beyond which impacts are ignored by decision makers while it is well understood that uncertainty and irreversibility will alter policy decisions aimed at alleviating environmental impacts the effect of spatial scales both physical and perceived is less understood when spatial scale is included in a real options model of environmental policy adoption results indicate that the importance and influence of spatial considerations depends on the level of uncertainty stringency of the proposed policy and flexibility of the policy decision recognizing spatial scale may force policy adoption to take place within a window of current damage when spatial scale is small or uncertainty high this window for policy adoption can close precluding policy adoption entirely this undermines well known results demonstrating that changes in uncertainty will only alter the timing of policy adoption in other instances the policy adoption window remains open but the option value increases faster than the benefits of the policy creating a scenario where it is always preferable to delay here the inclusion of an option value can prevent adoption of policies that would be adopted according to traditional cost benefit analysis in general policy decisions will be most affected by spatial considerations when the spatial scale is small damage is spreading fast and the uncertainty in damage spread is high

human ecosystem interactions a dynamic integrated model abstract we develop an interactive simulation model that links ecological and economic systems and explore the dynamics of harvest patterns as they simultaneously affect natural and human capital our models represent both single and multiple systems the level of natural capital is influenced by interactions of 1 natural capital growth and non human influenced depletion 2 ecological fluctuations 3 harvest rules and 4 biological transfers from one ecological system to another we focus first on isolated systems in which there are no biological transfers between units and humans rely for subsistence on the resource thus both the economic and ecological portions of the system are relatively independent of other systems in this case the maximum sustainable harvest rate depends on the local carrying capacity the stock growth rate and fluctuations in such ecological variables as rainfall and temperature which are extrinsic to the stock human harvest but nonetheless affect stock levels next we address spatially complex situations in which biological resources move from one spatial unit to others in these models the greater the potential movement of stocks across ecosystems the more any particular human sub system can increase its harvesting rate without danger of its own collapse although at a cost to neighboring subsystems

the control of invasive species on private property with neighbor to neighbor spillovers invasive pests cross property boundaries property managers may have private incentives to control invasive species despite not having sufficient incentive to fully internalize the external costs of their role in spreading the invasion each property manager has a right to future use of his own property but his property may abut others properties enabling spread of an invasive species the incentives for a foresighted property manager to control invasive species have received little attention we consider the efforts of a foresighted property manager who has rights to future use of a property and has the ability to engage in repeated discrete control activities we find that higher rates of dispersal associated with proximity to neighboring properties reduce the private incentives for control controlling species at one location provides incentives to control at a neighboring location control at neighboring locations are strategic complements and coupled with spatial heterogeneity lead to a weaker link public good problem in which each property owner is unable to fully appropriate the benefits of his own control activity future use rights and private costs suggest that there is scope for a series of coase like exchanges to internalize much of the costs associated with species invasion pigouvian taxes on invasive species potentially have qualitatively perverse behavioral effects a tax with a strong income effect e g failure of effective revenue recycling can reduce the value of property assets and diminish the incentive to manage insects on one s own property

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

specification of spatial dynamic externalities and implications for strategic behavior in disease control we propose a novel distance and density dependent specification of externalities that captures spatial dynamics within and between neighboring land parcels we use this specification to model the short and long distance diffusion and control of an infectious disease in two privately owned and ecologically connected vineyards using computational experiments to generate individual and aggregate payoffs our results suggest that ignoring the within parcel spatial dynamics in the model may overestimate the social cost of an externality we find that increased resource value heterogeneity defined as the difference in grape prices received by the two vineyards has a detrimental impact on aggregate payoffs

open access harvesting of wildlife the poaching pit and conservation of endangered species abstract we extend the traditional g s model of open access by defining a non concave harvesting function we demonstrate the possible existence of multiple equilibria and perverse comparative statics and show that small changes in the underlying economic parameters may trigger large jumps in species abundance finally we briefly discuss implications for management

differences and similarities between ecological and economic models for biodiversity conservation abstract in this paper we investigate an important obstacle which substantially complicates co operation between ecologists and economists but which has received little attention so far differences between the modelling approaches in economics and ecology to understand these differences 60 models addressing issues relevant to biodiversity conservation have been selected randomly from eight international economic and ecological journals the models have been compared according to a number of criteria including the models level of generality the mathematical techniques employed for formulation and solution of the models the level of complexity and the way time space and uncertainty are taken into account the economic models sampled are formulated and analysed analytically tend to be relatively simple and are mostly used to investigate general questions furthermore they often ignore space dynamics and uncertainty although some ecological models have similar properties there is also a substantial number of another type of ecological models that are relatively complex and analysed by simulation these models tend to be rather specific and often explicitly consider dynamics space and uncertainty the integrated ecological economic models are observed to lie in the middle between ecological and economic models an unexpected result is that they are not more complex than ecological and economic models as one could have expected from a simple merger of models from both disciplines but have an intermediate complexity

why do oil prices jump or fall this paper discusses theories that can explain the zig zags of oil prices in general and in particular the recent jump more precisely the following explanations are discussed homo oeconomicus pure profit maximization if demand is dynamic and convex price reaction function price increases and respectively declines depend on capacity utilization cartelization contingent on output or revenues of which the latter can lead to backward bending supply segments and multiple equilibria statistical descriptions mean reversion homo politicus i e arguments for price hikes that are rational public choice despite the long run economic loss finally two approaches are presented that emphasize demand uncertainty one extending the above mentioned dynamic demand framework and the other considers a dynamic game of non competitive suppliers with lumpy investments summing up a demand shock seems to be the most suitable explanation of today s high prices indeed a shock given that international energy agency iea and department of energy doe were promising just a couple of years ago that we are going to have lots of oil at low prices while others and in particular politics have surprisingly little or no explanatory power

a survey of the international evidence and lessons learned about unconventional monetary policies is a new normal in our future this study examines the effectiveness of unconventional monetary policies ump it considers whether these policies have been successful and where their effects remain uncertain we survey both the domestic financial market and macro economic effects of ump in the economies where these policies were introduced and their international spillover effects the paper considers the impact of a wide range of ump rather than the effects of specific policy instruments we also provide a retrospective on the important case of japan beginning in the late1990s and ask whether the eurozone s experience with ump is substantively different given its structure of policymaking finally we ask if the old normal is not in our future should the new normal in monetary policy routinely include what we now refer to as ump we conclude that ump can prevent economic collapse but are not designed to promote stronger long term economic growth apart from new communication strategies the use of ump under normal circumstances does not appear to be a sound monetary policy strategy failure to learn this lesson might also enable future policy makers to ask or expect too much from their central banks

limited entry licensing insights from a duration model limited entry is used to manage many fisheries effectiveness depends on a program s ability to control aggregate fishing power which fleet size and composition both affect this article analyzes fleet composition and attrition in a limited entry fishery the california red sea urchin fishery it explores the dynamics of heterogeneity in catch and revenue and applies duration analysis to study individual fisherman attrition using both individual level and time varying covariates the results show that the fleet is becoming more homogenous but also more potent and spatially mobile regulations such as size limits and season restrictions tend to increase attrition

the local effects of an innovation evidence from the french fish market in this paper we investigate the effect on quality quantity and prices of an innovative fishing gear introduced for a subsample of vessels on a single wholesale fish market in france estimations are conducted using transaction data over the 2009 2011 period during which the innovation was introduced using a difference in differences approach around the discontinuity we find that for the treated the innovation has a large effect on quality 29 2 percentage points and prices 23 2 percentage points a shift in caught fish species is observed and new targeted species are fished very intensively we also quantify the treatment effect on the treated market from aggregate market data using factor models and a synthetic control approach we find a sizable effect of the innovation on market quality which is consistent with non treated vessels adapting their fishing practices to remain competitive the innovation has no effect on market quantities and prices

fishing down the food chain revisited modeling exploited trophic systems abstract several highly cited papers suggest that commercial fishing is altering marine ecosystems by fishing down the food chain recent evidence calls into question the generality of the original findings but the papers all raise the question what mechanisms lie behind exploitation patterns in a trophic system this paper develops a simple model that shows how economic factors drive patterns of exploitation in a trophic system we show that while fishing down the food chain is possible there is no reason to suppose that the relevant economic factors favor such an outcome as we show other patterns are just as plausible we also discuss and show how an index of trophic level weighted harvest is not necessarily a good indicator of ecosystem health if biomass abundance is important

optimal harvesting of stochastic spatial resources abstract we characterize the optimal harvest of a renewable resource in a generalized stochastic spatially explicit model despite the complexity of the model we are able to obtain sharp analytical results we find that the optimal harvest rule in general depends upon dispersal patterns of the resource across space and only in special circumstances do we find a modified golden rule of growth that is independent of dispersal patterns we also find that the optimal harvest rule may include closure of some areas to harvest either on a temporary or permanent basis biological reserves reserves alone cannot correct open access but may under sufficient spatial heterogeneity and connectivity increase profits if appropriate harvest controls are in place outside of reserves

dynamic use of closures and imperfectly enforced quotas in a metapopulation the dynamic efficiency of closures in bioeconomic systems depends upon stock levels and in situ values that evolve over time and on relative costs of implementation a model of a harvested metapopulation is presented in which second best reduction of harvest from open access levels using input quotas balances monitoring costs against dynamic benefits of mitigating overharvesting temporary or permanent closures though generally still second best are preferable to quotas under certain conditions as demonstrated for a representative patch and time period interactions between patches are discussed numerical solutions illustrate comparative dynamics of closure use and show their potential benefits in a dynamic regulatory path

economic impacts of marine reserves the importance of spatial behavior abstract marine biologists have shown virtually unqualified support for managing fisheries with marine reserves signifying a new resource management paradigm that recognizes the importance of spatial processes in exploited systems most modeling of reserves employs simplifying assumptions about the behavior of fishermen in response to spatial closures we show that a realistic depiction of fishermen behavior dramatically alters the conclusions about reserves we develop estimate and calibrate an integrated bioeconomic model of the sea urchin fishery in northern california and use it to simulate reserve policies our behavioral model shows how economic incentives determine both participation and location choices of fishermen we compare simulations with behavioral response to biological modeling that presumes that effort is spatially uniform and unresponsive to economic incentives we demonstrate that optimistic conclusions about reserves may be an artifact of simplifying assumptions that ignore economic behavior

a note on the ecological economic modelling of marine reserves in fisheries abstract this paper gives an overview of the bioeconomic modelling of marine reserves and illustrates how economists have responded to the modelling results found in the ecological literature the economic analysis is shown to be far more pessimistic with regards to the potential of marine reserves as a fisheries management tool than what one finds in the purely ecological analysis the reason being the latter s neglect of issues such as discounting and economic incentive behaviour however economic analysis despite some of it being relatively advanced with regards to spatiality is still simplistic with regards to for instance ecosystem and habitat content a simple expansion of the existing bioeconomic models with regards to positive habitat effects of area closures is presented and analysed showing room for improved results from marine reserve implementation as compared to the existing analysis

decision making in patchy resource environments spatial misperception of bioeconomic models abstract we investigate the performance of subjects in a patchy resource environment in the experimental laboratory to expand the concept of stock misperception into spatial and non spatial components results indicate that substantial heterogeneity exists in the decision heuristics employed that can be used to identify subject types steady state and pulse fishing strategists while steady state strategists are only subject to spatial misperceptions pulse strategists are subject to both forms of misperception both subject groups overallocate effort to regions within the fishery that possess the highest rates of emigration inducing a spatial externality these spatial misperceptions are exacerbated by the spatial structure present

japan s deflation and the bank of japan s experience with nontraditional monetary policy this paper offers a brief summary of nontraditional monetary policy measures adopted by the bank of japan boj during the last two decades especially the period 1998 2006 when the so called zero interest rate policy zirp and quantitative easing qe were put in place the paper begins with a typology of policies usable at low interest and inflation rates they are strategy i management of expectations about future policy rates strategy ii targeted asset purchases and strategy iii qe alternatively qe may be decomposed into a pure attempt to inflate the central bank balance sheet qe0 purchases of assets in dysfunctional markets qe1 and purchases of assets to generate portfolio rebalancing qe2 strategy ii when nonsterilized is either qe1 or qe2 using this typology i review the measures adopted by the boj and discuss evidence on the effectiveness of the measures the broad conclusion is that strategies i and ii have affected interest rates while no clear evidence exists so far of the effectiveness of the pure form of strategy iii or qe0 strategy ii has been effective especially in containing risk liquidity premiums in dysfunctional money markets that is qe1 has been effective the effectiveness of qe2 however is less clear cut the strategies however have failed to bring the japanese economy out of the deflation trap so far i discuss some possible reasons for this and also implications for the current u s situation

policy effectiveness in spatial resource wars a two region model abstract we develop a spatial resource model in continuous time in which two agents strategically exploit a mobile resource in a two region setup to counteract the overexploitation of the resource the tragedy of commons that occurs when players are free to choose where to harvest the regulator can establish a series of spatially structured policies we compare the equilibria in the case of a common resource with those that emerge when the regulator either creates a natural reserve or assigns territorial user rights to the players we show that when technological and preference parameters dictate a low harvesting effort the policies are ineffective in promoting the conservation of the resource and in addition they lead to a lower payoff for at least one of the players conversely in a context of higher harvesting effort the intervention can help to safeguard the resource preventing extinction while also improving the welfare of both players

fixed effect estimation of highly mobile production technologies we consider fixed effect estimation of a production function where inputs and outputs vary over time space and cross sectional unit we exploit variability in the spatial dimension to identify time varying individual effects without parametric assumptions on the effects while estimation is unbiased asymptotics along the spatial dimension allow estimation of robust standard errors and asymptotic normality of the marginal products also if inference on the estimates of the individual effects is warranted then spatial asymptotics provide asymptotic normality while precluding an incidental parameters problem caused by asymptotics along the time or crosssectional dimensions we apply our results to a production function of bottom trawler fishing vessels in the flatfish fisheries of the bering sea we find significant spatial variability of output catch which we exploit in estimation of a harvesting function we conclude that vessel individual effects did not change across the period 2002 to 2004 we apply the theory of ranking and selection to determine that individual effects are not statistically significant across vessels

conducting monetary policy at very low short term interest rates can monetary policy committees accustomed to describing their plans and actions in terms of the level of a short term nominal interest rate find effective means of conducting and communicating their policies when that rate is zero or close to zero the very low levels of interest rates in japan switzerland and the united states in recent years have stimulated much interesting research on this question and have led some central banks to make changes in their operating procedures and communications strategies in this paper we will give a brief overview of current thinking on the conduct of monetary policy when short term interest rates are very low or even zero monetary policy works for the most part by influencing the prices and yields of financial assets which in turn affect economic decisions and thus the evolution of the economy when the short term policy rate is at or near zero the conventional means of effecting monetary ease lowering the target for the policy rate is no longer feasible however it would be a mistake to think that monetary policy was impotent we discuss three strategies for stimulating the economy at an unchanged level of the policy rate these involve i providing assurance to investors that short rates will be kept lower in the future than they currently expect ii changing the relative supplies of securities in the marketplace by altering the composition of the central bank s balance sheet and iii increasing the size of the central bank s balance sheet beyond the level needed to set the short term policy rate at zero quantitative easing we also discuss the costs and benefits of very low interest rates an issue that bears on the question of whether the central bank should take the policy rate all the way to zero before undertaking alternative policies

an open access fishery with rational expectations explain the evolution of the fish stock and the boat fleet as well as determine their equilibrium levels 2 while the changes in the fish stock are described by a biological rule entry and exit from the fishing industry are determined by how expectations are formed we examine a general model in which entry and exit are proportional to the present value of expected profits and compare two special cases of adaptive myopic expectations and rational expectations although both expectations mechanisms lead to the same equilibrium values they lead to different adjustment paths where expectations solely depend on current values myopic expectations it is well known that boats enter the fishery only when the fish stock is greater than its steady state stock 3 with rational expectations however boats may enter when the fish stock is much lower than its steady state value provided the boat fleet is sufficiently small this difference in adjustment is observable and in principle leads to an obvious test on how agents form expectations section 2 develops a general dynamic model for studying fisheries in section 3 we show that the model standardly used in the literature is equivalent to a myopic adaptive expectations model a rational expectations model is analyzed in section 4 the standard and rational expectations models are compared in section 5 section 6 illustrates this comparison using a simulation based on a schaefer model of the pacific halibut fishery section 7 presents the conclusions

viewpoint induced innovation in fisheries and aquaculture abstract some classical economists most notably malthus predicted that scarcity would undermine long term human well being john stuart mill in contrast predicted that the threat of scarcity creates incentives for innovation that help to avoid some of the worst outcomes popular claims of marine ecologists often apply the malthusian narrative to supplies of seafood yet global supplies have continued to grow we examine the modern seafood industry and evaluate mill s claims about innovation we argue that the mechanisms that mill discusses innovation in response to and in anticipation of scarcity account for much of what we see scarcities induce technological policy and market innovations that enable seafood supplies to grow and these innovations can build on each other the challenge for policy makers is to avoid knee jerk responses to malthusian narratives and craft policy responses that encourage innovation while recognizing physical limits of ocean resources

general equilibrium tragedy of the commons many poor economies depend on open access resources for their livelihoods households in resource based economies allocate their time and other factors between resource extraction and other activities as a result factors may shift from one sector to another as marginal returns change this has two important implications first it implies potentially strong linkages between resource and non resource sectors second it means that unmanaged resources cause inefficient allocations of inputs across all sectors and the effects of resource management spill into other sectors we construct a local general equilibrium model that accounts for inputs that over allocate to an open access resource and create a general equilibrium tragedy of the commons this model describes resource rent dissipation more adequately in economies with mobile factors than a model with slowly dissipating rents perfectly mobile factors dissipate rent in every period but endogenous wages cause labor and capital allocations to change with the resource stock we use the model to illustrate medium run impacts of a limit on capital in an artisanal fishery in honduras simulation results reveal that fishery management has economy wide impacts on prices and wages managers in developing countries thus should consider these linkages when implementing policies to conserve fish stocks

dynamic random utility modeling a monte carlo analysis applied studies of commercial fishing have largely ignored the intertemporal aspects of repeated site choices for many fisheries fishermen might choose a dynamically optimal cruise trajectory rather than myopic day to day strategies and a model that ignores these considerations will likely lead to biased parameter estimates and poor policy guidance a dynamic random utility model is developed that utilizes the same information as static site choice models but is entrenched in the principles of dynamic optimization using monte carlo analysis we evaluate the performance of this estimator as compared to the static model for a variety of simulated fishery types

deleveraging and monetary policy japan since the 1990s and the united states since 2007 japan s deleveraging became serious because the negative feedback loop was japan s deleveraging became serious because the negative feedback loop was not contained in its early stage of development the japanese government did not not contained in its early stage of development the japanese government did not act promptly to recapitalize banks that were suffering from the erosion of their act promptly to recapitalize banks that were suffering from the erosion of their capital buffer due to their large holdings of stocks as a result japan s banks only capital buffer due to their large holdings of stocks as a result japan s banks only slowly recognized bad loans while stopping lending to promising new projects slow slowly recognized bad loans while stopping lending to promising new projects slow but protracted asset sales resulted in a long period of asset price declines nonfi nanbut protracted asset sales resulted in a long period of asset price declines nonfi nancial companies perceived the deterioration of their balance sheets as permanent cial companies perceived the deterioration of their balance sheets as permanent and cut spending drastically as japan s economy stagnated the total amount of bad and cut spending drastically as japan s economy stagnated the total amount of bad loans turned out to be much larger than initially estimated loans turned out to be much larger than initially estimated

a model of regulated open access resource use abstract this paper develops a model of regulated open access resource exploitation the regulatory model assumes that regulators are goal oriented choosing target harvest levels according to a safe stock concept these harvest quotas are implemented by setting season lengths conditioned on the industry fishing capacity the industry enters until rents are dissipated conditioned on season length regulations harvest levels fishing capacity season length and biomass are determined jointly using parameter estimates from the long regulated north pacific halibut fishery predictions of these variables from the regulated open access model are compared to predictions that arise from the gordon model

bioeconomics of spatial exploitation in a patchy environment abstract this paper presents a model of renewable resource exploitation that incorporates both intertemporal dynamics and spatial movement the model combines the h s gordon vernon smith hypothesis of a rent dissipation process with ricardian notions that resources are exploited across space in a pattern dependent upon relative profitabilities the population structure is characterized in a manner consistent with modern biological ideas that stress patchiness heterogeneity and interconnections among and between patches generally we find the equilibrium patterns of biomass and effort across the system to be dependent upon bioeconomic conditions within each patch and the nature of the biological dispersal mechanism between patches we use simple examples to illustrate how the distribution of effort throughout the system reflects the heterogeneity and the spatial biological linkages

conservation in the optimal use of rangelands abstract in previous papers we have considered the optimal mix of biodiversity in semi arid rangelands focusing on the steady state this paper addresses the question of conservation in the optimal use of rangelands where conservation is understood to mean maintenance of the system in a natural state we consider a rangeland that may exist in one of two states in the natural state its dynamics are regulated by fire in the managed state its dynamics are regulated by grazing pressure by livestock we show that the optimal use of rangelands may include its maintenance in both states at different points in time depending on initial conditions and the set of relative prices

marine reserves a bio economic model with asymmetric density dependent migration abstract a static bioeconomic model of a marine reserve allowing asymmetric density dependent migration between the reserve and the fishable area is introduced this opens for habitat or ecosystem differences allowing different fish densities within and outside a reserve not described in earlier studies four management scenarios are studied a maximum harvest b maximum current profit c open access and d maximum sustainable yield msy in the reserve these are all analysed within the induced sustainable yield function isyf giving the relationship between the fish abundance inside the reserve and the harvesting taking place outside a numerical analysis shows that management focused on ensuring msy within the reserve under the assumption of symmetric migration may be negative from an economic point of view when the area outside the reserve is detrimental compared to the reserve furthermore choice of management option may also have negative consequences for long run resource use if it is incorrectly assumed that density dependent migration is symmetric the analysis also shows that the optimal area to close either a more or a less attractive ecosystem for the resource in question may differ depending on the management goal

joint production of food and wildlife uniform measures or nature oases intensive agriculture is often bad for wildlife does this imply that a goal to boost wildlife on agricultural land is best met through a general reduction in intensity we argue that such an approach may not be optimal since cost functions for provision of wildlife on agricultural land may be non convex due to fixed costs associated with such provision this implies that even when farms are identical it may be preferable to split them into groups of high providers and low providers we test our hypothesis in a study of the optimal management of mown grasslands in southern sweden where the two products are silage and successful reproduction of ground nesting birds and the variable controlled by the farmer is the date of the first mowing we show that the optimal solution is likely to involve some farmers maintaining profit maximizing practices while other identical farmers delay their first mowing significantly the superiority of such split solutions may have major implications for agricultural policy

an ecological economic modelling procedure to design compensation payments for the efficient spatio temporal allocation of species protection measures abstract using an interdisciplinary approach we present an ecological economic modelling procedure to design compensation payments for species protection we develop our procedure on the example of white stork protection in a spatio temporally structured landscape generated by human land use the proposed procedure is able to solve complex allocation problems such as the spatio temporal allocation of a budget among more than two areas with spatially differing species specific cost and benefit functions of any shapes furthermore the procedure delivers the efficient compensation payments not only qualitatively but quantitatively and is hence relevant to the implementation of species protection policies

a metapopulation model with private property and a common pool abstract a metapopulation illustrated by barnacles has a spatial distribution and a two stage life cycle in the model developed here space limits expansion introducing a profitable harvest activity of adults leads to harvest at only one site a solution driven by biological increasing returns the model is of interdisciplinary interest because the natural resource has common property characteristics in its larval stage but a private property character in its adult stage the model permits economic valuation of lost habitat

adjustment cost and supply response in a fishery a dynamic revenue function in industries where firms can adjust product mix in response to price changes the process can be delayed by adjustment costs an example is fishermen who change fishing grounds to target different species if adjustment costs are sufficiently large this may hamper the fishermen s response so that regulatory tools that are not efficient in the long run are useful in the short run moreover adjustment costs can influence the choice of species targeted in this paper dynamic supply equations are specified using a revenue function approach different hypotheses about the dynamics of the supply equations are tested for norwegian trawlers

diversity productivity and temporal stability in the economies of humans and nature abstract recent advances in ecology are of great potential relevance to economists here we present two ecological models of mechanisms of competition and coexistence and use these to derive how the primary productivity of ecosystems the amount of carbon dioxide removed from the atmosphere and stored by plants the efficiency of resource use and the spatial and temporal variability of productivity and resource use should depend on diversity we then discuss the relevance of these results to 1 ecosystem services and the economic value of diversity and 2 the functioning of any competitive system including the economy

unobserved diversity depletion and irreversibility the importance of subpopulations for management of cod stocks abstract diversity is often associated with resilience but in this model unobserved genetic or behavioral diversity can explain the collapse of supposedly regulated fish stocks such as cod recent studies have shown the existence of separate sub stocks of cod even at a very fine geographical scale we show that modeling a group of distinct stocks as if it were one large stock will tend to over estimate the growth and harvest potential if quotas are based on such over estimates the unobserved stock diversity can explain sudden stock collapses and unexpectedly slow recovery as observed for canadian cod it is a lack of information concerning diversity that leads to irreversibility the differences between the various stocks may be behavioral or genetic but cannot be observed by the fishermen or regulators who believe that there is a gradual decline in one big stock while in fact they are witnessing the successive disappearance of a series of sub stocks

spatial externalities and the common pool resource mechanism abstract this paper expands the common pool resource cpr game of walker et al 1990 to incorporate spatial structure with two spatially linked common pool resources subjects participated in a five player common pool resource game under three alternative spatial structures non spatial bi directional and uni directional linkages within the experiment results indicate that behavior in the uni directional cpr game yielded the highest average yields whereas those in the bi directional game were lower than in the non spatial game furthermore investment patterns in the uni directional game were proportionally lower in the sink cpr than those in the source cpr this behavior is consistent with the individual incentives of the game and highlights the importance of understanding the spatial structure present within our natural resources