direct payments spatial competition and farm survival in norway we argue that farm survival is influenced by neighboring farmers characteristics and in particular by the direct payments neighboring farmers receive the article shows empirically that these interdependencies are crucial for an assessment of the effects of direct payments on farm survival using spatially explicit farm level data for nearly all norwegian farms a spatial probit model is estimated to explain farm survival from 1999 to 2009 controlling for spatial farm interdependence we show that ignoring spatial interdependencies between farms leads to a substantial overestimation of the effects of direct payments on farm survival to our knowledge this article is the first attempt to empirically analyze the importance of neighboring interdependencies for the effects of direct payments on farm survival

how traders influence their neighbours modelling social evolutionary processes and peer effects in agricultural trade networks abstract marketing channel choices in agricultural trade networks affect the networks overall performance and influence rural livelihoods this study identifies key determinants of these choices among natural rubber traders in indonesia to evaluate four policy scenarios and their potential effects on rural incomes since traders marketing decisions are based on past interactions resulting trade networks are formed in recursive processes and can be understood as complex adaptive systems due to inherent endogeneity in these systems process based approaches such as agent based modelling abm can be effective in understanding them using a self gathered primary dataset from jambi province indonesia we implement and parameterise an abm to simulate the formation of the rubber trading network and analyse the effects on rural livelihoods of four hypothetical policy scenarios improved micro credit availability increased access to education better infrastructure and transportation capacity and market information availability the model is calibrated through a genetic algorithm which maximises the similarity between the simulated network and the actual network observed in the data results indicate that sellers decisions on a buyer are primarily determined by debt obligations and past peer interactions the most influential sellers have a similar level of formal education as their peers and live in close physical proximity results of the policy scenario analysis suggests that policies aimed at reducing sellers dependence on credit from buyers and increasing education are the most effective policies for improving value chains and reducing poverty in the region under consideration

the long run and short run impact of captive supplies on the spot market price an agent based artificial market an agent based model is developed that matches the results of xia and sexton 2004 as well as our generalization of their model we relax xia and sexton s assumption of no supply response by captive feeders which reduces the price depressing effect of captive supplies finally the agent based model is used to simulate packers choosing both captive supply quantities and spot market quantities packers in the relaxed agent based model choose no captive supplies and thus reach the cournot solution the research narrows the gap between theoretical models and the empirical work on captive supplies that shows little effect on prices but a gap remains

using portfolio theory to improve resource efficiency of invested capital limited literature provides concrete theory based methods for quantifying the effects of sharing capital this paper describes the potential contribution of portfolio theory to quantify the effects and optimize the employment of capital human tangible financial and service employing capital in a theoretical and quantitative manner in the context of sustainability insights illustrate how portfolio principles can yield benefits including the fulfillment of needs using fewer resources consistent with sustainability in particular pooling assets to meet uncertain demands from different users of an asset pool may yield benefit from diversification effects suggests future research avenues such as the management of high value critical value and expiring resources to support sustainability

which factors influence the expansion of bioenergy an empirical study of the investment behaviours of german farmers the german government is planning to increase the share of renewable energy sources in this context it is important to understand the decision making behaviour of farmers regarding investments in renewable energy systems that generate energy from biomass and farmers reactions to investment support measures to study this behaviour we conduct a survey and confront farmers with a hypothetical opportunity to invest in a biogas plant our findings reveal that farmers have heterogeneous investment thresholds their investment decisions are mainly driven by capital costs and the subjective perception of the risk resulting from the investment other decision parameters like sustainability and non monetary objectives that are also examined in this paper play only minor roles however bounded rationality is an important factor moreover the influence of an investment subsidy was analysed only about half of the amount of the subsidy as expected according to normative forecast models is reflected in an increased willingness to invest furthermore farmers who have previously invested in bioenergy plants show lower investment thresholds and have stronger reactions to the subsidy regarding the expansion of renewable energies these findings are meaningful for policy impact analysis

consuming use orientated product service systems a consumer culture theory perspective abstracts research suggests that product service systems pss may usefully form part of the mix of innovations necessary to move society toward more sustainable futures however pss implementation rates are disappointingly low and an implementation gap has emerged drawing on consumer culture theory cct this paper provides insights to help resolve this issue in business to consumer markets since consumption of use orientated pss is analogous to access based consumption six dimensions of access are set out to analyse a case study of infant car seat provision five outcomes are derived from the analysis and these include partial identification with accessed product and interplay of use and symbolic value this analysis questions the view that pss do not create sufficient value to overcome a preference for ownership in western societies rather pss consumption is likely to arise when both functional and symbolic value are extracted by consumers and when pss are promoted to appropriate consumer groups such as nomads further research is needed to explore these phenomena and address the issues they raise in pss design processes

modelling land use deforestation and policy a hybrid optimisation heterogeneous agent model with application to the bolivian amazon abstract we introduce a hybrid simulation model simpachamama designed to explore the complex socio environmental trade offs of alternative policy bundles and policy sequencing options for stemming deforestation and reducing poverty in tropical countries designed and calibrated to the initial conditions of a small forest village in rural bolivia the model consists of a an optimising agricultural household module of heterogeneous agents that make individually optimal land use decisions based on factor endowments and market conditions b an encompassing general equilibrium shell module that endogenously determines wages and links the agricultural labour market and rural urban migration rates and c a novel user controlled policy maker module that allows the user to make real time choices over a variety of public and environmental policies that in turn impact land use welfare and migration over a 20 year simulation period the results highlight trade offs between reductions in deforestation and improvements in household welfare that can only be overcome either when international redd payments are offered or when decentralized deforestation taxes are implemented the sequencing of policies plays a critical role in the determination of these results

an exploration of livestock development policies in western china limited agricultural land potential poorly integrated markets and low rural incomes are all interrelated problems for agricultural households in western china within the wide range of development options available this paper focuses on the impact of forage growing subsidies and reducing livestock feed trade barriers on agricultural household incomes and enterprise mixes in the qingyang prefecture of gansu province china a heterogeneous agent model is used to assess the local consequences of these two policies data from a survey conducted in 2009 are used as inputs into the model the results indicate that a simultaneous reduction in livestock feed trade barriers and an introduction of forage growing subsidies lifts net household incomes by approximately 10 different scenarios have different impacts on incomes land allocation decisions and grain purchases with heterogeneity also found among household income responses livestock development policies have the potential to lift household incomes however there are tradeoffs between income and grain self sufficiency

how many stocks make a diversified portfolio we show that a well diversified portfolio of randomly chosen stocks must include at least 30 stocks for a borrowing investor and 40 stocks for a lending investor this contradicts the widely accepted notion that the benefits of diversification are virtually exhausted when a portfolio contains approximately 10 stocks we also contrast our result with the levels of diversification found in studies of individuals portfolios

does structure matter the impact of switching the agricultural policy regime on farm structures abstract this paper investigates the relationship between structural change in agriculture and a policy regime switch at the regional level using the agent based spatial and dynamic simulation model agripolis we simulate structural change for two different farm structures in response to a policy change results show that structural adjustment differs depending on the initial structure

a further exploration in the theory of exchange rate regimes in an interesting paper in this journal elhanan helpman 1981 develops a simple two country model to compare the welfare levels that are achieved under different exchange rate regimes in a world characterized by perfect foresight his basic finding is that equilibrium consumption allocations and hence welfare levels are identical under a floating exchange rate system and a one sided peg fixed exchange rate regime this result is due to helpman s assumption that output is determined exogenously which allows a separation of the real and monetary sides of the economy the purpose of this paper is to extend helpman s model by making two alterations in his setup 1 to allow production to be endogenously determined as a function of labor force participation and 2 to allow welfare levels to be dependent on labor service as well as on consumption the main conclusion then obtained is that a country may achieve a higher welfare level under a flexible exchange rate regime than under a fixed exchange rate regime since it is able to choose an optimal rate of inflation or currency depreciation

changes in beef packers market power after the livestock mandatory price reporting act an agent based auction controversy remains about the effectiveness of the 1999 livestock mandatory price reporting act mpra we determine the likely changes in beef packers market power after the mpra by using an agent based first price common value auction past research has employed cournot models but we use an auction model which more closely resembles the actual cattle procurement process we find that feeders benefit from the mpra regardless of whether price uncertainty decreases for packers and or feeders if the packers price uncertainty is reduced the feeder benefits from an increase in competition between the packers if the feeder s price uncertainty is reduced the feeder benefits from imposing more accurate reserve prices copyright 2013 oxford university press

economic crisis in a shortage economy it is not unusual for reforming socialist economies to relax wage controls without hardening budget constraints on enterprises or freeing consumer goods prices this policy can be dangerously destabilizing while higher wages permit workers to purchase more of some goods they also tend to exacerbate shortages and to breed waste and corruption beyond a certain level economywide wage hikes will worsen worker welfare this is true regardless of whether deficit goods are strictly rationed are sold randomly at official prices to queuing workers or are offered to workers by insiders only at black market prices however the form of allocation does influence the levels of output and welfare

product services as a research field past present and future reflections from a decade of research in the last decade many researchers institutes and programs in the eu paid attention to product service systems pss given this massive effort it is time to take stock is pss research a theoretical field in its own right is the pss concept indeed the road to the factor 10 world is it the road to enhanced competitiveness what is needed to really use the potential of the concept this paper discusses these questions summarizing the analysis done in the pss review book new business for old europe various eu sponsored projects and the conceptual approach chosen in a new research network on sustainable consumption and production called score 2006 elsevier ltd all rights reserved

anticipated devaluations currency flight and direct trade controls in a monetary economy mendation for a country facing a balance of payments deficit this advice is often resisted by country governments instead direct trade controls such as tariffs quotas and subsidies are frequently used in this paper i propose an economic explanation for the reluctance to devalue and the use of trade controls namely the currency flight that can be expected to occur if the devaluation is anticipated in an effort to avoid or offset the effects of this currency flight countries may use direct controls i shall analyze the properties of using import tariffs and export subsidies with or without an anticipated devaluation to affect the balance of payments and obtain the social optimum

the benefits of inflation in the economies with price controls and the cash in advance black markets abstract i study the welfare implications of an accelerated growth of nominal money supply in an economy with price controls i proceed by embedding barzel s 1974 classical rationing by waiting arguments in a general equilibrium model with money in an endowment economy studied below binding price controls lead to queuing and the black market money is introduced through a cash in advance cia constraint on the black market purchases in sharp contrast to the common view i show that an increase in the growth rate of the money supply is welfare improving both on impact and in the long run this is because it reduces the steady state waiting line by inducing a substitution towards the inflation tax free leisure i discuss the robustness of this finding the results strongly support the case for a complete elimination of price controls ahead of inflation stabilization

sprayed to death path dependence lock in and pest control strategies theoretical literature on the economics of technology has emphasized the effects on technological trajectories of positive feedbacks in a competition among technologies that all perform a similar function the presence of increasing returns to adoptions can force all but one technology from the market furthermore the victor need not be the superior technology this paper provides an empirical study of one technological competition which illuminates this theoretical work it uses theoretical results to explain why chemical control of agricultural pests remains the dominant technology in spite of many claims that it is inferior to its main competitor integrated pest management copyright 1996 by royal economic society

agent based spatial models applied to agriculture a simulation tool for technology diffusion resource use changes and policy analysis abstract this paper presents a spatial multi agent programming model which has been developed for assessing policy options in the diffusion of innovations and resource use changes unlike conventional simulation tools used in agricultural economics the model class described here applies a multi agent cellular automata ca approach by using heterogeneous farm household models and capturing their social and spatial interactions explicitly the individual choice of the farm household among available production consumption investment and marketing alternatives is represented in recursive linear programming models adoption constraints are introduced in form of network threshold values that reflect the cumulative effects of experience and observation of peers experiences the model s economic and hydrologic components are tightly connected into a spatial framework the integration of economic and hydrologic processes facilitates the consideration of feedback effects in the use of water for irrigation the simulation runs of the model are carried out with an empirical data set which has been derived from various data sources on an agricultural region in chile simulation results show that agent based spatial modelling constitutes a powerful approach to better understanding processes of innovation and resource use change

quantifying value chain analysis in the context of livestock systems in developing countries the analysis of value chains has augmented our knowledge on the complexities inter linkages distributional benefits and institutional arrangements of production and marketing channels in developing countries however the analysis remains relatively qualitative and case specific with limited ability to rank or assess the impact of alternative interventions or to analyze sufficiently the complex market dynamics and feedbacks present in livestock systems this paper offers theoretical and applied insights on ways to improve the analytical rigor of the value chain methodology that combines both qualitative and quantitative approaches

multi agent simulations to explore rules for rural credit in a highland farming community of northern thailand thanks to recent advances in the field of distributed artificial intelligence agentbased models abm can now be used to run simulations of social phenomena based on their computerized representations and to apply experimental methods in social sciences axelrod 1997 gilbert and troitzsch 1999 jager 2000 in the field of renewable resource management and environmental sciences several abm simulation platforms offer the possibility to explore interactions between social and ecological dynamics costanza and ruth 1998 bousquet et al 1998 lansing 2002 in these complex systems the social and economic dynamics can be viewed as a set of interactions among heterogeneous agents generating aggregate phenomena that are different from the behaviour of groups of average individuals considered in classical economic thinking rouchier and bousquet 1998 such a view was adopted in the research presented here

can intensification of cattle ranching reduce deforestation in the amazon insights from an agent based social ecological model abstract deforestation in the amazon with its vast consequences for the ecosystem and climate is largely related to subsequent land use for cattle ranching in addition to conservation policies proposals to reduce deforestation include measures to intensify cattle ranching however the effects of land use intensification on deforestation are debated in the literature this paper introduces the abacra model a stylized agent based model to study the interplay of deforestation and the intensification of cattle ranching in the brazilian amazon the model combines social learning and ecological processes with market dynamics in the model agents adopt either an extensive or semi intensive strategy of cattle ranching based on the success of their neighbors they earn their income by selling cattle on a stylized market we present a comprehensive analysis of the model with statistical methods and find that it produces highly non linear transient outcomes in dependence on key parameters like the rate of social interaction and elasticity of the cattle price we show that under many environmental and economic conditions intensification does not reduce deforestation rates and sometimes even has a detrimental effect on deforestation anti deforestation policies incentivizing fast intensification can only lower deforestation rates under conditions in which the local cattle market saturates

simulating soil fertility and poverty dynamics in uganda a bio economic multi agent systems approach declining soil fertility and increasing rural poverty are major problems facing sub saharan agriculture bio economic modeling has been used to analyze the complex interaction between ecological sustainability and rural poverty as well as to explore policy options promoting sustainable development this paper shows that these models can be further advanced by adopting an agent based modeling approach this gives a more realistic representation of diversity in socioeconomic and biophysical terms allows local interaction between households and can yield an ex ante assessment of the distributional consequences of policy intervention this paper describes the modeling approach and illustrates it with an empirical application to two village communities in the lake victoria crescent of uganda it is shown how the model system can be calibrated with and validated against empirical data the model is used to analyze the potential effect of short term credit mineral fertilizer and improved maize seed on poverty and sustainability simulation results suggest substantial reductions in poverty although the incidence of poverty would remain high and these innovations alone would have little effect on the long term ecological sustainability of the system

agent based modeling for ex ante assessment of tree crop innovations litchis in northern thailand this study uses an agent based model for ex ante assessment of agricultural innovations the model builds on whole farm mathematical programming mp and extends the methodology with a spatial representation of the system the heterogeneity of farm households and landscapes and the interaction between farm households we apply the model in a northern thai watershed to study the potential of four innovations to increase the profitability of litchi orchards cost benefit analysis shows that each innovation would increase the profitability of litchi growing however the results of the agent based model show that at current price levels these innovations alone would not be enough to stem the decline in the area under litchis the model was validated and the sensitivity of the results tested for variations in the irrigated water supply and liquidity we report on how farmers responded to these results and discuss the implications for other areas in northern thailand

from ownership to service use lifestyle the potential of car sharing abstract the shift from ownership to service use often promoted in concepts of sustainability has recently become available in private vehicle mobility currently 38 000 people in a number of european cities are participating this example is used here to analyze the characteristics of people sharing one material product as well as to investigate which services they actually render different views on the latter imply different evaluations of the size of the market potential and different conclusions on the effectiveness of various policy instruments when service use is a separate lifestyle policy instruments have to ultimately foster it directly rather than changing economic costs at the margin only