ecosystem services from eye opening metaphor to complexity blinder abstract what started as a humble metaphor to help us think about our relation to nature has become integral to how we are addressing the future of humanity and the course of biological evolution the metaphor of nature as a stock that provides a flow of services is insufficient for the difficulties we are in or the task ahead indeed combined with the mistaken presumption that we can analyze a global problem within a partial equilibrium economic framework and reach a new economy project by project without major institutional change the simplicity of the stock flow framework blinds us to the complexity of the human predicament the ecosystem services approach can be a part of a larger solution but its dominance in our characterization of our situation and the solution is blinding us to the ecological economic and political complexities of the challenges we actually face

a stochastic model of investment marginal q and the market value of the firm this paper presents closed form solutions for the investment and valuation of a competitive firm with a cobb douglas production function and a constant elasticity adjustment cost function in the presence of stochastic prices for output and inputs the value of the firm is a linear function of the capital stock the optimal rate of investmentis an increasing function of the slope of the value function with respect to the capital stock marginal q a mean preserving spread of the distribution of future price increases investment an increase in the scale of the random component of a price can increase decrease or not affect the rate of investment depending on the sign of the covariance of this price with a weighted average of all prices this abstract was borrowed from another version of this item

adjustment costs from environmental change abstract the paper is concerned with the case whereby the distribution of a firm s productivity shocks changes without the knowledge of the firm over time the firm learns about the nature and extent of the change in the distribution of the shock and adjusts incurring adjustment costs in the process the long run loss in profits due to the shift in the distribution we term the equilibrium response the transitory loss in profits incurred while the firm is learning about the distribution shift is termed the adjustment cost the theory is then applied to the problem of measuring adjustment costs in the face of imperfectly observed climate change in agriculture the empirical part of the paper involves estimating a restricted profit function for agricultural land in a five state region of the midwest us as a function of prices land characteristics actual weather realizations and expected weather we then simulate the effect of an unobserved climate shock where learning about the climate shock is by observing the weather and updating prior knowledge using bayes rule we find adjustment costs to climate change are 1 4 of annual land rents

poverty comparisons over time and across countries in africa abstract we use demographic and health surveys dhs to compare poverty at two or more points in time within and between african countries our welfare measure is an index resulting from a factor analysis of various household characteristics durables and household heads education an advantage of this measure is that for intertemporal and intraregional comparisons we need not rely on suspect price deflators and currency conversion factors the wide availability and similarity of questionnaires of the dhs facilitate comparisons over both time and countries our results generally show declines in poverty during the previous decade largely due to improvements in rural areas

poverty transition in rural vietnam the role of migration and remittances abstractthis study combines insights of the new economics of labour migration with the asset based approach to welfare dynamics using panel household data from vietnam this method allows us to determine whether poverty transitions induced by remittances are actually structural that is based on asset growth and therefore long term or stochastic that is based only on short term increases in income which implies a risk of falling back into poverty to control for endogeneity of remittances we use household fixed effects and instrumental variables estimation the paper shows that remittances have a positive impact on asset growth and that the impact differs with welfare status and ethnicity

the economics of poverty traps and persistent poverty an asset based approach abstract longitudinal data on household living standards open the way to a deeper analysis of the nature and extent of poverty while a number of studies have exploited this type of data to distinguish transitory from more chronic forms of income or expenditure poverty this paper develops an asset based approach to poverty analysis that makes it possible to distinguish deep rooted persistent structural poverty from poverty that passes naturally with time due to systemic growth processes drawing on the economic theory of poverty traps and bifurcated accumulation strategies this paper briefly discusses some feasible estimation strategies for empirically identifying poverty traps and long term persistent structural poverty as well as relevant extensions of the popular foster greer thorbecke class of poverty measures the paper closes with reflections on how asset based poverty can be used to underwrite the design of persistent poverty reduction strategies

designing payments for environmental services in theory and practice an overview of the issues abstract payments for environmental services pes have attracted increasing interest as a mechanism to translate external non market values of the environment into real financial incentives for local actors to provide environmental services es in this introductory paper we set the stage for the rest of this special issue of ecological economics by reviewing the main issues arising in pes design and implementation and discussing these in the light of environmental economics we start with a discussion of pes definition and scope we proceed to review some of the principal dimensions and design characteristics of pes programs and then analyze how pes compares to alternative policy instruments finally we examine in detail two important aspects of pes programs their effectiveness and their distributional implications pes is not a silver bullet that can be used to address any environmental problem but a tool tailored to address a specific set of problems those in which ecosystems are mismanaged because many of their benefits are externalities from the perspective of ecosystem managers pes is based on the beneficiary pays rather than the polluter pays principle and as such is attractive in settings where es providers are poor marginalized landholders or powerful groups of actors an important distinction within pes is between user financed pes in which the buyers are the users of the es and government financed pes in which the buyers are others typically the government acting on behalf of es users in practice pes programs differ in the type and scale of es demand the payment source the type of activity paid for the performance measure used as well as the payment mode and amount the effectiveness and efficiency of pes depends crucially on program design

rural to urban migration human capital and agglomeration a new general equilibrium model that links together rural to urban migration the externality effect of the average level of human capital and agglomeration economies shows that in developing countries unrestricted rural to urban migration reduces the average income of both rural and urban dwellers in equilibrium various measures aimed at curtailing rural to urban migration by unskilled workers can lead to a pareto improvement for both the urban and rural dwellers in addition the government can raise social welfare by reducing the migration of skilled workers to the city moreover without a restriction on rural to urban migration a government s efforts to increase educational expenditure and thereby the number of skilled workers may not increase wage rates in the rural or urban areas

transaction costs of carbon offset projects a comparative study abstract the land use change and forestry sector can be a cost effective contributor to climate mitigation in at least three ways providing carbon offsets through carbon sequestration in biomass and soils reducing emissions of methane and other greenhouse gases and producing biofuels that replace fossil fuels the presence of carbon markets should help encourage these activities however most carbon trades to date have occurred in the energy sector a major obstacle to carbon trades from land use systems is the presence of high transaction costs of converting a carbon offset into a tradable commodity so the prevailing market carbon prices may not provide enough incentive for adoption this paper presents a model of the exchange of carbon offsets between a project developer and a group of landholders the model is solved to derive project feasibility frontiers that show the minimum number of contracts necessary to make a project feasible at any given carbon price the model is applied to two case studies smallholder agroforestry in indonesia and partial reforestation of family farms in australia under two types of contract purchase of carbon flows and rental of carbon stocks the paper concludes by identifying possible strategies to reduce transaction costs while maintaining project integrity

revisiting the concept of payments for environmental services this article revisits the payments for environmental services pes concept and reviews existing pes definitions based on weberian philosophy of science it is argued that an ideal pes type strongly embedded in pes theory is needed to understand their logic many broader empiricist definitions fail to distinguish pes from the larger generic family of positive environmental incentives thus eroding their meaning by excessive vagueness arguably pes definitions should focus on describing a functional tool rather than normatively integrating desirable pes outcomes a modified narrow pes definition is proposed outlining conditionality as the single defining feature avoiding the buyer seller terms and linking pes to offsite externalities extensive explanatory guidelines address many valid conceptual concerns raised in the recent pes literature

the economics of conjunctive groundwater management with stochastic surface supplies abstract groundwater management with stochastic surface flows and artificial recharge is considered theoretical analysis characterizes the decision rules and establishes conditions for convergence of socially optimal and common property withdrawals and pumping lifts to limiting probability distributions an empirical application to kern county california finds that optimal withdrawals are generally increasing in hydraulic head and decreasing in surface flows however nonmonotone behavior is observed in some instances artificial recharge is not observed in the limiting distribution due to an interaction of several factors optimal management implies relatively small gains over unregulated groundwater use when preferences are risk neutral

balance sheet in the redd are global estimates measuring the wrong costs abstract this article challenges some of the assumptions underpinning the un programme to reduce emissions from deforestation and forest degradation redd in developing countries firstly it argues that the cost effectiveness of redd may have been exaggerated as current estimates ignore some cost categories as well as the evolution of drivers whilst redd remains a low hanging fruit for climate mitigation if all costs were included estimates would be at the high end of the currently accepted range secondly the article highlights that redd will be affected by a large funding gap at least until the entry into force of a new climate protocol in 2020 this gap is due as much to the poor status of public finances in donor countries as to the languishing state of carbon markets and it calls for a revision of the assumptions regarding the design of the programme finally it is advocated that in order to contribute to the development of the programme economic research on redd should consider different policy options assessing their efficiency and identifying measures that increase their cost effectiveness

does the nonfarm economy offer pathways for upward mobility evidence from a panel data study in ethiopia summary empirical studies across many developing countries routinely document a positive correlation between participation in rural nonfarm employment and households wealth or income this paper explores whether nonfarm employment leads to higher consumption expenditure growth in ethiopia we find that 1 households consumption expenditure growth is positively correlated with the initial share of nonfarm income 2 the growth elasticity of nonfarm income share is higher for wealthier households and 3 the main source of growth for nonfarm participants comes from the higher rates of return participants enjoy on their human and physical capital

rural poverty dynamics in kenya structural declines and stochastic escapes we use panel survey data and household event histories to explore patterns of rural poverty dynamics in kenya over the period 2000 2009 we find substantial mobility across poverty categories using economic transition matrices drawing on asset based approaches we distinguish stochastic from structural poverty transitions few households successfully escaped poverty through asset accumulation up to 35 of the upwardly mobile while a large proportion of households up to 66 declining into poverty experienced structural transitions using household event histories we find significant differences across structural poverty transition classes in livelihood strategies household level shocks and other factors

network effects and the dynamics of migration and inequality theory and evidence from mexico international migration is costly and initially only the middle class of the wealth distribution may have both the means and incentives to migrate which can increase inequality in the sending community however the migration networks formed lower the costs for future migrants which can in turn lower inequality this paper shows both theoretically and empirically that wealth has a nonlinear effect on migration and then examines the empirical evidence for an inverse u shaped relationship between emigration and inequality in rural sending communities in mexico after instrumenting we find that the overall impact of migration is to reduce inequality across communities with relatively high levels of past migration we also find some suggestive evidence for an inverse u shaped relationship among communities with a wider range of migration experiences

adjustment costs uncertainty and the behavior of the firm this paper examines the effects of demand and cost uncertainty on a firm s investment output and pricing decisions but unlike most earlier studies in which demand and cost are simply not known at the time an output or pricing decision is made here i consider uncertainties over future demand and costs it will be seen that the effects of such uncertainties depend critically on the characteristics of the firm s adjustment costs i treat demand uncertainty in a dynamic context by letting the market demand function shift randomly but continuously through time according to a stochastic process this means that today s demand is known exactly but future demand may be larger or smaller and has a variance that increases with the time horizon likewise uncertainty over factor costs is characterized by treating those variables as stochastic processes i combine this characterization of uncertainty with a dynamic model of the firm in which some factor inputs can be adjusted freely in response to stochastic demand changes but other factors are quasi fixed in that adjustment costs are incurred when they are changed in this model the firm s price and output are random processes but we can examine the firm s behavior in expected value terms of interest is whether the presence of uncertainty should cause competitive or monopolistic firms to invest and produce more or less than they would otherwise how the effects of uncertainty are influenced by the presence of risk aversion and how the use of inventories can alter the impact of uncertainty on capacity and sales of course these questions have been addressed by others in the past among the earliest studies of demand uncertainty are those of edwin mills 1959 1962 and samuel karlin and charles carr 1962 mills examined a single period monopolistic firm that sets both output and price and showed that additive demand uncertainty i e the demand function is of the form q q p u where u is a random variable leads to a lower price if marginal cost is constant so that the firm reduces the expected loss from discarding unsold production karlin and carr confirmed for both the static case and the multiperiod case with inventory carryover that additive uncertainty tends to reduce the price and increase the output of a risk neutral firm while multiplicative uncertainty does the opposite other papers have been concerned with the way in which the error term enters the demand function additively multiplicatively or nonlinearly the implications of choosing price ex ante instead of output the implications of risk aversion and the use of inventories for example agnar sandmo 1971 and david baron 1970 showed that a risk averse competitive firm will produce less when the price is a random variable or subject to an additive error term but a riskneutral firm will not alter its production hayne leland 1972 extended these results to a monopolistic firm whose demand can depend in a general way on a random error term for example q q p u and showed that uncertainty reduces the production of a

the poor stay poor household asset poverty traps in rural semi arid india summary although identifying household level poverty dynamics would have important implications for poverty reduction policies empirical evidence is still scant this paper employs a novel semiparametric panel data estimator that combines the advantages of estimation methods in the existing literature and applies it to a uniquely long panel data set to examine poverty dynamics in three villages in rural semi arid india structural immobility is pervasive the currently poor are likely to remain poor suggesting a structural poverty trap while all households face static asset holdings higher castes larger landholders and more educated households are significantly less likely to be poor

how funding source influences the form of redd initiatives the case of market versus public funds in brazil abstract the mechanism to reduce emissions from deforestation and forest degradation redd which is being implemented by the united nations framework convention on climate change is considered essential to provide economic incentives for the adoption of forest based mitigation measures against global climate change this article analyses the key characteristics of redd pilot initiatives in brazil from different perspectives concerning the concept of payment for environmental services while exploring how these characteristics relate to the funding models adopted regardless of whether they are sourced from public funds or via the carbon market data collected from publicly available databases are analysed using hypothesis tests ten variables from 89 pilot initiatives approved by the voluntary carbon market or the fundo amazonia amazon fund are examined findings show that initiatives under each funding model have distinct characteristics in terms of stakeholders criteria for incentive concession time frames geographical reach as well as measurement report and verification mrv practices differences are consistent with distinct theoretical conceptions on incentive based economic instruments

managing risks from climate impacted hazards the value of investment flexibility under uncertainty abstract incomplete knowledge about climate change and the related uncertainty in climate prediction makes adaptation inherently difficult we introduce a real options framework to determine the optimal adaptation to catastrophic risk that takes into account climate change uncertainty the framework can be used to select the optimal adaptation project from a number of alternative projects or to determine the optimal investment sequence of the considered projects in applying the model to the management of bushfire risk at a local government area we find that the framework can significantly increase the value of adaptation investment above the current net present value and also improve upon deterministic dynamic models we also find that it is important to consider sequential investment to preserve investment flexibility under the uncertainty of climate change when decision makers can afford multiple investment projects the loss associated with the use of a simple net present value rule can be substantial and it is important to use a deterministic dynamic model or a real options model

direct conservation payments in the brazilian amazon scope and equity implications abstract this article looks into the scope and equity implications of applying payments for environmental services pes as a redd implementation mechanism in the brazilian amazon we establish a set of economic and institutional preconditions for pes to become a feasible and cost effective conservation mechanism we proceed with a macro scale spatial analysis and overlay of opportunity costs deforestation patterns carbon services and land tenure in order to assess where these conditions hold we then screen how the benefits of potential pes schemes might be distributed across different socioeconomic groups of service providers in different land tenure categories our economic quantitative analysis though sensitive to documented assumptions suggests that under current carbon prices the economic preconditions are in place to pay for avoided deforestation in over half of threatened forests over the next decade unfortunately the same optimism does not apply to institutional preconditions land grabbing insecure tenure overlapping claims and lacking information on private tenure constitute real medium term impediments to pes if payments were to accrue to current landholders regardless of current tenure insecurities large landowners who account for about 80 of all deforestation would reap the highest benefits though per capita benefits other tenure categories are also high schemes that closely align payments with opportunity costs are preferable for cost effectiveness and not necessarily more inequitable in outcomes essentially pes systems cannot substitute command and control measures the former depend on the latter for basic governance systems to secure effective rights of exclusion which land stewards essentially need in order to become reliable service providers

a simple competitive model with production and storage we study a rational expectations partial equilibrium model of a market for a single storable commodity whose output each period is a function of previous period effort on production and a realization of a shock that affects equally all producers i he final demand is non random and depends only on each period s price risk neutral producers make production and storage decisions based on forecasts of future price distributions existence of equilibrium is proved and for the case of i i d shocks several comparative statics results are established as well as the existence and stability of a unique stationary distribution and whose output at each period is a multiplicative function of previous period s planting and of the realization of a shock that affects equally all producers the final demand for this good is non random and depends only on this period s price this describes approximately markets for agricultural products which are not traded internationally and where most of the price uncertainty stems from supply shocks risk neutral producers make their decisions based on forecasts of future price distributions and of known cost functions of storage and production to maximize their discounted profits in order to close the model an assumption on how such price forecasts are made is needed we assume that agents make equilibrium forecasts i e that their forecast is common and that when producers act taking the forecasted prices as given they make decisions that yield the forecasted prices as equilibrium prices this is of course what has been sometimes called rational expectations the assumption of equilibrium expectations and the presence of risk neutral pro ducers will imply that the equilibrium variables may be obtained by considering a related market surplus maximization problem 1 this places strong restriction on the stochastic process of equilibrium prices for the case where the basic shocks are assumed to be independently and identically distributed over time one may thus show that equilibrium prices are a function of a certain state variable the total stocks kept from last period plus this period s output and this allows us to derive properties of equilibrium solutions our main results concerning this case are a storage is a non increasing function of price and expected production a non decreasing one b the elasticity of expected future prices with respect to today s prices is positive and less than one c this elasticity is non constant being zero for high enough prices d the price process follows a renewal process if prices are low

uncertainty and irreversibility in groundwater resource management abstract optimal exploitation of renewable groundwater resources when extraction affects the probability of occurrence of an irreversible event is studied the term irreversible signifies that the event occurrence renders the resource obsolete it is found that uncertainty concerning the event occurrence has a profound effect under certainty when the stock level below which the event occurrence has a profound effect the optimal state process converges to a unique equilibrium state under uncertainty when the event occurrence level is unknown we identify equilibrium intervals and show that optimal processes initiated elsewhere converge to a boundary of one of these intervals inside an equilibrium interval the expected loss due to the event occurrence is so high that it does not pay to extract in excess of recharge even though under certainty doing so would be beneficial

the new economics of labor migration this paper reviews selected theoretical and empirical developments in the field of labor migration economics the migration behavior of individuals differs in accordance with their perceived relative deprivation those who are relatively more deprived tend to have stronger incentive to migrate than those who are relatively less deprived moreover a reference group characterized by more income inequality is likely to generate more relative deprivation highly skilled workers are also more likely to migrate migration decisions are often made jointly by the migrant and nonmigrant with a contractual arrangement regarding the sharing of costs and returns the exchange of commitments to share income provides coinsurance of particular interest are the determinants of the speed of adoption of migration as an innovation and the characteristics associated with the delay in the adoption of innovation new econometric techniques including techniques for the analysis of qualitative dependent variables techniques that correct for sample selection bias and those for the analysis of longitudinal data have substantially benefited empirical research in this area new methods that can correct for the biased estimate of the wages particular individuals would receive at 2 or more locations at the same point in time allow researchers to test locational decsion making models estimates of these structural models of labor migration support the hypothesis that individuals respond to income incentives in making the decsion to migrate further research is needed on the pazzling observation that migrant workers earn less than native born workers with similar characteristics during the 1st few years after migration but more thereafter other topics that need further research include the macroeconomic effects of migration the microeconomic and macroeconomic relationships between aging and labor migration and the migration behavior of dual earner families

migration and incomes in source communities a new economics of migration perspective from china the objective of this paper is to understand the effects of china s migration on source communities and to discuss their policy implications we draw from new economics of labor migration nelm theory to understand how migration and migrant remittances can relax or tighten market constraints in china s rural economy using simultaneous equation econometric techniques and household survey data from china we estimate net sectorspecific effects of migration on rural household income focusing on farm production and self employment our econometric findings indicate that the loss of labor to migration has a negative effect on household cropping income in source areas however we provide evidence that remittances sent home by migrants positively compensate for this lost labor effect contributing to household incomes directly and indirectly by stimulating crop and possibly self employment production this finding offers evidence in support of the nelm hypothesis that remittances loosen constraints on production in the imperfect market environments characterizing rural areas in less developed countries taking into account both the multiple effects of migration and the change in household size participating in migration increases household per capita income between 14 and 30 percent migration and incomes in source communities a new economics of migration perspective from china china is experiencing the largest peacetime flow of labor out of agriculture ever witnessed in world history solinger 1999 rozelle et al 1999 despite the rapid expansion of labor migration china s work force is still disproportionately employed in agriculture compared to other countries at similar levels of per capita gdp taylor and martin 2001 hence as china s economy continues to expand the flow of labor to urban areas will continue and even accelerate johnson 1999 the massive flow of labor away from farms has intensified research interest in china s migration in recent years however as in the broader literature on migration in less developed countries most recent studies on china s migration have focused on determining the size and composition of the labor flow macroeconomic implications of increased migration and the effects of migration on urban areas zhao 1999 yang 1999 1997 less emphasis has been placed on researching the effects of migration on the rural communities that migrants leave even though evidence shows that the rural household in the village of origin is typically the central concern of all those involved in migration both those who leave and those who stay behind exceptions include wang and zuo 1999 bai 2001 moreover the recent increase in migration has left policy makers particularly concerned regarding the way source communities will be affected moa 1999 they are concerned that as labor flows away from farms food production and crop income will decline potentially threatening china s food security furthermore policy makers are concerned about the increasing gap between urban and rural household incomes if migration exacerbates this gap some fear that as it grows rural residents eventually will flood cities ill equipped to absorb them others fear that discontent over a rising urban rural income gap could even spill over into political unrest yang 1999 because china s markets and other modern economic institutions are still relatively undeveloped migration may play a pivotal role in creating or overcoming constraints caused by the lack of well functioning markets and or institutions knight and song 1999 benjamin and brandt 2000 the new economics of labor migration nelm literature analyzes migration as a household decision rather than as an individual decision stark 1991 the nelm hypothesizes that rural households facing imperfect market environments decide

exploring poverty traps and social exclusion in south africa using qualitative and quantitative data abstract recent theoretical work hypothesises that a polarised society like south africa will suffer a legacy of ineffective social capital and blocked pathways of upward mobility that leaves large numbers of people trapped in poverty to explore these ideas this paper employs a mix of quantitative and qualitative methods novel econometric analysis of asset dynamics over the 1993 98 period identifies a dynamic asset poverty threshold that signals that large numbers of south africans are indeed trapped without a pathway out of poverty qualitative analysis of this period and the period 1998 2001 more deeply examines patterns of mobility and confirms the continuation of this pattern of limited upward mobility and a low level poverty trap in addition the qualitative data permit a closer look at the specific role played by social relationships while finding ample evidence of active social capital and networks these are more helpful for non poor households for the poor social capital at best helps sta

adjustment costs uncertainty and the theory of investment the case of non renewable natural resources abstract this paper examines the effects of mineral price and extraction cost uncertainty on the investment program of a competitive resource extracting industry that faces convex costs of adjustment the results show that depletion of mineral reserves will slow down if the marginal adjustment cost function is concave or linear whereas the effect will be ambiguous if the function is convex

adjusting to climate change implications of increased variability and asymmetric adjustment costs for investment in water reserves abstract in this paper we study the determination of optimal water storage capacity in a region taking into account that the supply of the resource the flow into the reserve is uncertain that a measure of the uncertainty the variance is likely to increase with climate change that building capacity is costly and that the development of water resources may entail alsoenvironmental costs we find that water storage capacity in the long run ispositivelyrelated to increases in uncertainty if the marginal benefit of water withdrawal isconvexand that for the case of costly reversibility of investment a range of inaction for investment appears and the stability of water storage capacity with respect to changes in variance increases

what is the impact of international remittances on poverty and inequality in latin america workers remittances have become a major source of income for developing countries however little is still known about their impact on poverty and inequality using a large cross country panel dataset the authors find that remittances in latin american and caribbean lac countries have increased growth and reduced inequality and poverty these results are robust to the use of different instruments that attempt to correct for the potential endogeneity of remittances household survey based estimates for 10 lac countries confirm that remittances have negative albeit relatively small inequality and poverty reducing effects even after imputations for the potential home earnings of migrants

information and the dynamics of environmental protection the concept of the critical period earlier work on environmental decisions under uncertainty is extended from two periods to many permitting treatment of a richer variety of problems implications for pollution control policy of several different kinds of ecosystem recovery dynamics are considered in the context of improving information about ecosystem behavior and preferences for environmental goods multiperiod analogs of the two period concept of quasi option value are developed

migration remittances and agricultural productivity in china in our paper we have used the new economics of labor migration framework to trace the complex linkages that exist among migration remittances and agricultural productivity in china constraints in the operation of on farm labor and capital or insurance markets or institutions provide households with a motivation to migrate and distort on farm operations when labor leaves in our household sample the net impact of migration and remittances on maize production is negative excerpt

stochastic wealth dynamics and risk management among a poor population we use herd history data collected among pastoralists in southern ethiopia to study stochastic wealth dynamics among a poor population although covariate rainfall shocks plainly matter household specific factors including own herd size account for most observed variability in wealth dynamics we find no support for the tragedy of the commons hypothesis past studies may have conflated costly self insurance with stocking rate externalities biophysical shocks move households between multiple dynamic wealth equilibria the lowest suggesting a poverty trap according to nonconvex path dynamics these findings have broad implications for development and relief strategies among a poor population vulnerable to climatic shocks a vast economic literature on risk management rests explicitly or implicitly on the classic friedmanite permanent income hypothesis studies of portfolio management consumption smoothing social insurance and the like all depend on the canonical assumption that stochastic income realisations are drawn from a stationary income distribution leading to consumption smoothing off a stable asset base the possibility of asset accumulation connects this literature to the immense literature on the theory and empirics of economic growth

reconciling theory and practice an alternative conceptual framework for understanding payments for environmental services article i nfo this article provides an alternative and novel theoretical approach to the conceptualization and analysis of payments for environmental services pes we devote special emphasis to institutional and political economy issues which have been somewhat neglected in the literature on pes we argue that the coasean and pure market approach dominating the conceptualization of pes in the literature cannot be easily generalized and implemented in practice by contrast taking into account complexities related to uncertainty distributional issues social embeddedness and power relations permits acknowledging the variety of contexts and institutional settings in which pes operate the alternative approach presented in this introductory article to the special section may be more appealing to pes practitioners since while avoiding restrictive and prescriptive standpoints it allows some key sources of complexities they usually deal with on the ground to be more easily understood

does migration make rural households more productive evidence from mexico abstract the migration of labour out of rural areas and the flow of remittances from migrants to rural households are an increasingly important feature of less developed countries this paper explores ways in which migration influences incomes and productivity of land and human capital in rural households over time using new household survey data from mexico our findings suggest that a massive increase in migration to the united states increased per capita incomes via remittances and also by raising land productivity in migrant sending households they do not support the pessimistic view that migration discourages production in migrant sending economies nor the view implicit in separable agricultural household models that migration and remittances influence household incomes but not production

remittances household expenditure and investment in guatemala the author uses a large household data set from guatemala to analyze how the receipt of internal remittances from guatemala and international remittances from the united states affects the marginal spending behavior of households on various consumption and investment goods contrary to other studies the author finds that households receiving remittances actually spend less at the margin on consumption food and consumer goods and durables than do households receiving no remittances instead of spending on consumption households receiving remittances tend to spend more on investment goods like education health and housing the analysis shows that a large amount of remittance money goes into education at the margin households receiving internal and international remittances spend 45 and 58 percent more respectively on education than do households with no remittances these increased expenditures on education represent investment in human capital like other studies the author finds that remittance receiving households spend more at the margin on housing these increased expenditures on housing represent a type of investment for the migrant as well as a means for boosting local economic development by creating new income and employment opportunities for skilled and unskilled workers