property rights externalities and resource degradation locating the tragedy abstract resource degradation in the third world is largely driven by the demands of farm households for fuelwood and land for agriculture since resources are often controlled through indigenous systems of property the tragedy of the commons has been used to explain resource degradation as a result private property is suggested as a solution to resource degradation a dynamic model capable of examining household incentives for resource use under private and common property is developed results of the model reject the conventional wisdom that gives rise to the presumed optimality of private individual property in natural resources and the correlated indictment of group management regimes

learning about a new technology pineapple in ghana this paper investigates the role of social learning in the diffusion of a new agri cultural technology in ghana we use unique data on farmers communication patterns to define each individual s information neighborhood conditional on many potentially confounding variables we find evidence that farmers adjust their inputs to align with those of their information neighbors who were surpris ingly successful in previous periods the relationship of these input adjustments to experience further indicates the presence of social learning in addition applying the same method to input choices for another crop of known technol ogy correctly indicates an absence of social learning effects jel d83 013 033 q16

designing forest taxes with varying government preferences and budget targets abstract a model of forest policy design is constructed to examine how government preferences affect the choice of forest taxes government preferences are modelled by assuming that the government faces a binding revenue constraint and cares about the provision of public goods from forests the equilibrium is second best given the imposition of the revenue constraint on the government s decision making our results show that a revenue constrained government will make different choices than a government that does not face revenue constraints this has important implications for the choice of property and harvest taxes as well as pigouvian forest taxes

household level determinants of adoption of improved natural resources management practices among smallholder farmers in western kenya abstract integrated natural resources management inrm of which integrated soil fertility management isfm is a component offers considerable promise for increasing food production in kenya it nonetheless remains unclear whether isfm inrm techniques lend themselves easily to adoption by smallholder farmers using panel data collected in western kenya in 1989 and 2002 this study finds that resource constraints limit many farmers adoption of isfm inrm techniques the size of the farm owned by a household the value of its livestock off farm income family labor supply and the educational attainment and gender of the household head all had a significant positive effect on the likelihood of adoption similar factors were found to be statistically significant in discouraging abandonment of the practices under study there thus seem to exist reinforcing feedback between investments in soil fertility management and household wealth as measured by asset endowments our findings raise important questions as to whether isfm and related techniques are really affordable to poorer smallholder farmers

integrating technology traits and producer heterogeneity a mixed multinomial model of genetically modified corn adoption this article proposes a model of technology adoption that integrates demand for individual traits of new technologies with the potential for heterogeneity based on farm and farmer characteristics the model is applied to recent genetically modified corn adoption data from minnesota and wisconsin farmers using a mixed multinomial logit mmnl model to estimate the effects of traits and farm and farmer characteristics on adoption outcomes this approach allows explicit recovery of estimates of farmers shadow prices for individual technology traits results show the importance of producer and regional heterogeneity in preferences for seed traits

supply chain design and adoption of indivisible technology in this paper we develop a framework to analyze adoption of indivisible technologies by relatively small farms using a threshold diffusion model it shows that different supply chains may emerge to enable the adoption of indivisible technologies independent technology dealers may buy the indivisible equipment and rent it to farmers when the gain from adoption is not affected by scale or ownership of the technology also larger farmers may buy the technology equipment and rent it renting the machine per se or providing a set of services that includes use of the machinery for the farmer buying the service to smaller farmers especially when there are gains from scale or ownership the paper derives equilibrium prices and quantities in the output equipment and technology rental market these equilibrium prices and quantities depend on the heterogeneity of farmers and the features of the technology introduction of the new indivisible technology will benefit larger adopting farmers and consumers but may hurt non adopters we illustrate our conceptual findings with empirical examples

social networks and technology adoption in northern mozambique despite their potentially strong impact on poverty agricultural innovations are often adopted slowly using a unique household dataset on sunflower adoption in mozambique we analyse whether and how individual adoption decisions depend upon the choices of others in the same social networks since farmers anticipate that they will share information with others we expect farmers to be more likely to adopt when they know many other adopters dynamic considerations however suggest that farmers who know many adopters might strategically delay adoption to free ride on the information gathered by others we present empirical evidence that shows that the relationship between the probability of adoption and the number of known adopters is shaped as an inverse u in line with information sharing the network effect is stronger for farmers who report discussing agriculture with others the data contains information which is needed to ameliorate the identification issues that commonly arise in this context in particular social networks are precisely identified and in addition we can control for village heterogeneity and endogenous group formation

the impact of agricultural biotechnology on yields risks and biodiversity in low income countries abstract this paper shows that the current generation of transgenic crop varieties has significant potential to improve economic welfare in low income countries these varieties might increase crop yields in low income countries in cases when pesticides have not been used they will reduce negative health effects of chemicals when they replace them with low transaction costs appropriate infrastructure and access to intellectual property multiple varieties of transgenics will be introduced the gain from transgenics will be reduced and crop biodiversity may be lost when only a small set of varieties is transgenetically modified the adoption of transgenics will also be affected by risk and credit considerations

policy relevant nonconvexities in the production of multiple forest benefits abstract this paper challenges common assumptions about convexity in forest rotation models which optimize timber plus nontimber benefits if a local optimum occurs earlier than the globally optimal age policy based on marginal incentives may achieve suboptimal results policy relevant nonconvexities are more likely if i nontimber benefits dominate for young stands while the optimal age depends primarily on timber benefits or ii nontimber benefits dominate for mature stands and also determine the optimal age nonconvexities may create either temporary or persistent difficulties policymakers may improve efficiency by exploiting the relationship between the timber only optimum and the global optimum

the returns from schooling in a diversified rural economy controlling for the endogeneity of activity choice and considering both household head and family schooling we findevid ence of high returns from schooling in both crop andnoncrop activities as schooling levels increase the returns from schooling shift away from crop production failure to control for activity selection andfamily schooling is likely to result in biasedestimates of the returns from schooling in individual activities copyright 2000 oxford university press

input choices in agriculture is there a gender bias summary this paper examines evidence of gender biases in the decisions of agricultural households utilizing data from international crops research institute for the semi arid tropics s village level studies in india 1975 85 the main empirical finding is that households with a high proportion of boys tend to use some agricultural inputs including fertilizers and irrigation services more intensively than households with girls this pattern is more pronounced among wealthier households but does not appear to be driven solely by bequest motives or male child labor productivity

spillovers from modern supply chains to traditional markets product innovation and adoption by smallholders there is an emerging body of literature analyzing how smallholder farmers in developing countries can benefit from modern supply chains however most of the available studies concentrate on export markets and fail to capture spillover effects that modern supply chains may have on local markets here we analyze the case of sweet pepper in thailand which was initially introduced as a product innovation in modern supply chains but which is now widely traded also in more traditional markets using survey data from smallholder farmers and econometric techniques we show that sweet pepper cultivation contributes significantly to higher household incomes strikingly at this stage participation in modern supply chains does not lead to higher incomes than supplying sweet pepper to traditional markets however the results also indicate that missing land titles weak infrastructure conditions and limited access to information constituted serious constraints during the early phases of sweet pepper adoption such constraints need to be overcome so that smallholder farmers are better prepared for the prompt reactions needed under rapidly changing market conditions

information flows and social externalities in a tanzanian banana growing village this article analyses the role of social networks as facilitators of information flows and banana output increase based on a village census full information is available on the socio economic characteristics and banana production of farmers kinship group members neighbours and informal insurance group members the census data enable us to use individual specific reference groups and include exogenous group controls to tackle standard difficulties related to identification and omitted variables bias when analysing social effects for the survey village of nyakatoke in tanzania the results suggest that information flows exist within all types of groups analysed but output externalities are limited to kinship groups using networks may offer scope for effective information flows on agricultural techniques but our evidence suggests that not just any local network will have a social externality impact requiring a clear understanding of local social networks for maximum impact

adoption of agricultural innovations in developing countries a survey this paper reviews various studies which have provided a description and possible explanation to patterns of innovation adoption in the agricultural sector the survey points out that the tendency of many studies to consider innovation adoption in dichotomous terms adoption nonadoption may not be appropriate in many cases where the actual decisions are defined over a more continuous range more attention needs to be given to the socio cultural and institutional environment in area studies so that their interrelation with economic factors affecting adoption can be inferred the presence of several interrelated innovations is another aspect that needs to be considered more carefully in future research since a number of simultaneous decisions may be involved furthermore the possibility of regular sequential patterns in adopting components of a new technological package should be specifically addressed in future studies finally the impact of differential adoption rates on land holding distribution merits attention in future research

virtual price approach to short term timber supply under credit rationing abstract duality and virtual prices are used in a fisherian two period savings consumption model to simplify the analysis of nonindustrial private timber supply under credit rationing a possible way to measure the degree of credit rationing perceived by nonindustrial private forest owners is proposed slutsky type decompositions for the derivatives of the credit rationed timber supply function are calculated and the credit rationed derivatives are related to corresponding derivatives in a perfect capital market further the impact of the degree of credit rationing on the substitution and income effects of the exogenous variables are discussed and it is shown that the total effects are independent of the degree of credit rationing the results help to interpret parameter estimates of private nonindustrial timber supply functions especially if micro data are available

the demand for information and the diffusion of a new product abstract the paper examines the implications of the ability of a consumer to learn about the characteristics of a new product on the diffusion of the product over time the demand for information by the consumer is shown to generate a sigmoid diffusion curve for total sales of the product further it is shown that over time the elasticity of demand along the diffusion curve increases

poverty consumption risk and soil conservation abstract this paper studies the impact of poverty and uninsured consumption risk on incentives to invest in soil conservation a stochastic dynamic model is used to show how consumption risks and costs of investment influence incentives to adopt soil conservation measures on low income farms the model is calibrated using production data from hillside farms in the philippines simulations with the model demonstrate how the value of soil conservation depends on the cost of investing the risk characteristics of the soil conservation method and differences among households in capacity to bear risk model predictions are compared with empirical adoption patterns as described by a probit model and nonparametric kernel regressions of adoption probability empirical findings show how differences in farm size tenure security risk exposure and access to credit help to explain patterns of soil conservation adoption implications for policy are discussed

the role of education on the adoption of chemical fertiliser under different socioeconomic environments in ethiopia studies on input adoption consider education as one of the most important factors that affect adoption decisions however very little is known about the spill over effect of intra household education on the adoption process and about the impact of education on adoption decisions under different socioeconomic conditions we investigate these two issues using a discrete choice model the results indicate that the decision making process is a decentralised one in which educated adult members of the household actively participate in the decision making process this casts doubt on the traditional assumption that the household head is the sole decision maker the results reveal that there is a substantial and statistically significant intra household spill over effect of education on the adoption decision of households the results of the study also show that the coefficient of the education and the environment interaction variable is negative and statistically significant this demonstrates that education and socioeconomic environments could be substitutes in modern environments and complementary in traditional ones this implies that the expansion of education in traditional areas may be more attractive than in modern areas since education is usually the only means to enhance the ability of farmers to acquire synthesise and respond to innovations such as chemical fertiliser

regulated price and stock policies abstract setting administered domestic prices according to just c i f of f o b border price is advisable only if the direction of trade is certain and all groups interests are weighted equally if the good randomly may be imported of exported prices and stocks should be determined simultaneously on the basis of domestic demand and supply conditions as well as border prices a framework is proposed for testing which optimizing model an ldc government employs when administering price and stock levels the framework suggests zimbabwe policy makers have treated maize as an export crop weighting consumers interests moderately below those of producers and government

technology adoption and agricultural price policy market interventions such as price supports or fertilizer subsidies can lead to gains from speeding up adoption of new technologies but the policies distort resource allocation a framework is developed for optimizing policies in light of the adoption allocation trade off based on adoption coefficients and production parameters from third world agriculture levels and duration of policies are estimated sensitivity analyses are performed gains are small at best and may be zero or negative in view of farmer costs of adjustment and deadweight losses from taxes profit technology adoption if new technologies are desirable why not use price supports or input subsidies to encourage faster technology adoption while frequently raised in policy deliberations this question has received little serious analysis particularly neglected has been the conflict or trade off between a gains in output as producers switch from old to new technologies and b the losses from resource use distortions brought about by price policies when output prices are raised or prices of inputs such as fertilizer are lowered the

rural finance and agricultural technology adoption in ethiopia does the institutional design of lending organizations matter summary it has now become almost a stylized fact that sustained agricultural growth is central to rapid poverty reduction and economic development yet world poverty is largely concentrated in the agrarian societies which have the potential for agricultural productivity growth this is particularly true for sub saharan african countries where the gaps between potential and actual yields remain high minimizing this gap through the promotion of modern inputs such as fertilizer and modern seeds has been at the core of almost all development strategies in ethiopia among other initiatives the country has promoted microfinance institutions and member owned financial cooperatives to alleviate credit constraints of the smallholder farmers this paper analyzes the impacts of these institutions using household survey data and a propensity score matching technique we examine the effects that institutional financial services have on farmers adoption of agricultural technology in ethiopia the results suggest that access to institutional finance has a significant positive impact on both the adoption and extent of technology use however when impacts are disaggregated by type of financial institution and farm size heterogeneities are observed in particular financial cooperatives have a greater impact on technology adoption than microfinance institutions and the results appear to vary depending on farm size and types of inputs the paper concludes with implications for policies to promote adoption of modern agricultural inputs

the economics of water conserving technology adoption in tunisia an empirical estimation of farmer technology choice economic theory tells us that increases in the relative prices of natural resources should cause farmers to switch to techniques that use fewer farming resources the adoption of resource conserving technology is one possible response that can lead toward a more environmentally sustainable outcome do farmers respond to changes in natural resource prices and quality by adopting available resource conserving technology this article investigates a case study of decisions made by tunisian farmers as to whether or not they should invest in water conserving drip irrigation technology as a function of natural resource prices and quality along with farm and farmer characteristics in contrast to many studies of technology adoption this work uses both the standard revealed preference analysis of who adopts and a direct elicitation of the reasons for adoption or nonadoption by farmers by reviving an ancient methodology the direct question to elicit real preferences from farmers the research goes beyond the restrictive assumptions of the commonly used random utility models the combination of these techniques allows triangulation on the causes of technology adoption and helps insure that the results are more than a statistical artifact excerpt

technology adoption under price uncertainty abstract the paper examines the impact of changes in the variance of output prices on the bias and intrafirm diffusion rate of technological change the results indicate that a reduction in the variance of output prices will increase the rate of adoption and the intrafirm diffusion speed of yield increasing technologies the opposite is true for cost reducing technologies

learning from neighbours when payoffs from different actions are unknown agents use their own past experience as well as the experience of their neighbours to guide their decision making in this paper we develop a general framework to study the relationship between the structure of these neighbourhoods and the process of social learning we show that in a connected society local learning ensures that all agents obtain the same payoffs in the long run thus if actions have different payoffs then all agents choose the same action and social conformism obtains we develop conditions on the distribution of prior beliefs the structure of neighbourhoods and the informativeness of actions under which this action is optimal in particular we identify a property of neighbourhood structures local independencewhich greatly facilitates social learning simulations of the model generate spatial and temporal patterns of adoption that are consistent with empirical work

agro export production and peasant land access examining the dynamic between adoption and accumulation abstract new technologies and export opportunities have often contributed to dualistic agrarian structure and intense social conflict in latin american a switching regression model developed in this paper explicitly links export adoption and land accumulation patterns controlling for pre existing differentiation processes applied to survey data gathered from peasant households in guatemala the model provides evidence of equitable structural change induced by a recent export boom in vegetable crops however the optimism of these results is tempered by consideration of the unfavorable longer term market dynamics confronting small scale producers

production economics of private forestry a comparison of industrial and nonindustrial forest owners this paper compares the producrion behavior of industrial and nonindustrial privateforestland owners in the southeastern u s using a restricted profit function profits aremodeled as a function of two outputs sawtimber and pulpwood one variable input regeneration effort and two quasi fixed inputs land and growing stock although anidentical profit function is rejected the results indicate behavior consistent with pmfit maximizing motives under both ownerships the two ownerships have similar responsesto input and output price changes both in the shon run and in the long run however nonindustrial owners appear to place a higher value on their standing timber andforestland than do industrial owners the difference in estimated shadow valuesindicates that significant nonmarket benefits are being captured by nonindustriai ownersand the benefits are reflected in their production behavior

the impact of improved maize varieties on poverty in mexico a propensity score matching approach summary this study examines the adoption of improved maize germplasm in oaxaca and chiapas in mexico it employs a propensity score matching approach to analyze the impact of the adoption of improved maize varieties on household income and poverty reduction using cross sectional data of 325 farmers from the two regions the findings reveal a robust positive and significant impact of improved maize variety adoption on farm household welfare measured by per capita expenditure and poverty reduction specifically the empirical results suggest that adoption of improved maize varieties helped raise household per capita expenditure by an average of 136 173 mexican pesos thereby reducing their probability of falling below the poverty line by roughly 19 31

dynamics of variety change on wheat farms in pakistan a duration analysis abstract decades after the green revolution sustaining wheat productivity remains an important policy goal for the government of pakistan understanding the speed of diffusion of new wheat varieties can contribute to this goal we apply duration analysis to identify the factors that shorten the time until a farmer replaces one modern variety by another and test hypotheses concerning two recurring themes of the green revolution farm size differences and the role of information sources in seed diffusion we find that time to adoption averages only 4 years but is shorter on larger farms factors that speed variety change also differ by farm size extension and media sources of information significantly influence adoption among larger farmers relative to information gained through social relationships but this is not the case for marginal farmers traits related to consumption quality speed adoption on smaller wheat farms where families both sell and consume their wheat higher yields drive adoption for the most subsistence oriented marginal group

optimal design of forest taxation with multiple use characteristics of forest stands the paper studies optimal forest taxation under uncertainty about future timber price when private forest owners value amenity services of forest stands and forest stands have public goods characteristics it is assumed that preferences of forest owners can be described by a quasi linear intertemporal utility function which reflects risk aversion in terms of consumption and constant marginal utility in terms of amenity services the comparative statics of current and future harvesting in terms of timber price risk site productivity tax and yield tax are first developed it is shown that given the optimal site productivity tax which is independent of the timber harvested and thus non distortionary it is desirable to introduce the yield tax at the margin it both corrects externality due to the public goods characteristic of forest stands and serves as a social insurance device the optimal yield tax is less than 100 and depends on the social value of forest stands timber price risk and properties of compensated timber supply in the general case the inverse elasticity rule according to which the optimal yield tax is negatively related to the size of the substitution effects may not hold under certainty the desirability of the yield tax given the optimal site productivity tax depends only on the existence of public goods characteristic and is thus a pure pigouvian tax

free trade zones with harris todaro unemployment a note on young miyagiwa abstract this paper attempts to generalise the young miyagiwa results for an economy with a free trade zone and harris todaro unemployment by incorporating intersectoral mobility of domestic capital and an upward sloping supply function of foreign capital our analysis reveals that under reasonable assumptions creating a free trade zone may lead to a loss in national welfare further there may arise a conflict between the twin objectives of increasing employment and increasing national welfare

intermediate goods and the formation of duty free zones abstract if a country forms a duty free zone by lowering tariffs on intermediate goods and taxes on foreign capital used in the zone then resources are attracted from the surrounding domestic zone this can worsen the effects of the distortions due to the tariffs remaining in the domestic zone and can lower the host country s national income and welfare this tends to occur if 1 there is less substitutability between the intermediate and labor than between these factors and capital 2 there is currently a small foreign owned sector in which the share of labor in total costs is large relative to the share of the imported intermediate in the foreign sector and relative to the share of labor in total costs in the domestic zone ironically under the latter circumstances the host country is likely to regard a duty free zone as an attractive option

optimal taxation timber and externalities abstract the paper presents a model of the relationship between timber taxation and externalities optimal pigouvian taxation formulas are derived within this framework for common taxes a simulation model of douglas fir is used to estimate the size and direction of these effects the results show that taxation policy can have a marked impact on the production of externalities depending on tree species and land productivity

unemployment and the formation of duty free zones abstract a number of authors have suggested that the formation of a duty free zone may reduce the welfare of the host country their analyses assumed full employment for a country suffering unwemployment of the harris todaro type we show that the value of national output at world prices increases with the formation of a duty free zone which involves the reduction of tariffs on intermediate imports into the zone

the effect of household wealth on the adoption of improved maize varieties in zambia abstract production and price risks that could render input use unprofitable sometimes prevent rural households from benefiting from input technological change the household s ability to cope with such risks and hence benefit from input technological change is often positively related to its wealth or stock of productive assets empirical evidence however suggests a non linear relationship between wealth and adoption of new agricultural technologies so that within a rural community households on the lower wealth continuum behave differently from those on the higher level using farm level data collected from 300 randomly selected households in three districts of zambia in 2004 2005 crop season this paper first stratifies households into poorly and well endowed households based on their access to productive assets and estimates separate double hurdle models for the adoption of improved high yielding maize ihym varieties for each group the results show that factors influencing the adoption and use intensity of ihym varieties differ between the two groups this draws attention to the need for recommending wealth group specific interventions to increase the adoption and use intensity of such varieties and their subsequent impacts on food security and general livelihoods of the households the explicit testing for the possibility that differences in household wealth affect the way in which other variables influence adoption decisions is the paper s unique contribution to the adoption literature

seeing is believing evidence from an extension network experiment extension is designed to enable lab to farm technology diffusion decentralized models assume that information flows from researchers to extension workers and from extension agents to contact farmers cfs cfs should then train other farmers in their communities such a modality may fail to address informational inefficiencies and accountability issues the authors run a field experiment to measure the impact of augmenting the cf model with a direct cf training on the diffusion of a new technology all villages have cfs and access the same extension network in treatment villages cfs additionally receive a three day central training on the new technology they track information transmission through two nodes of the extension network from extension agents to cfs and from cfs to other farmers directly training cfs leads to a large statistically significant increase in adoption among cfs however higher levels of cf adoption have limited impact on the behavior of other farmers

value chain clusters and aquaculture innovation in bangladesh abstract farmers adopting and implementing innovations such as new technologies and new products often require collaborative inter segment innovation by other actors in other segments of the value chain such as wholesalers implementing new product innovations such as supply of commercial fish feed and chemicals and buying and marketing non traditional fish species we tested whether the clustering and thus economies of agglomeration with implied lower transaction costs encourage and facilitate farmers to innovate that potential determinant of farmer choices has not been studied in agriculture or aquaculture or indeed the food sector we use a unique data set from our own primary survey of the aquaculture value chain in bangladesh including micro data for 1500 fish farm households and 20 districts 77 villages for meso level data we calculate an index to include both horizontal agglomeration and vertical interconnections among actors in the value chain we find being in an area with a high clustering index is associated with a higher probability of farmers using more modern inputs and growing non traditional commodity fish species controlling for farmers other characteristics as well as proximity to cities

the effects of agricultural development policies on income distribution and technological change in agriculture abstract a framework for analyzing the effects of policies on income distribution is introduced for the case where farmers have both discrete adoption decisions relating to fixed cost and continuous adoption decisions relating to land allocation distributional effects depend on the underlying distributions of farm size risk preferences and credit availability absolute and relative equity effects of various policies are shown to depend critically on which of these factors are major barriers to adoption and on the stochastic relationship of returns to various cropping activities a fixed cost subsidy appears to be a dominant policy from an equity standpoint in most cases

time to change what to sow risk preferences and technology adoption decisions of cotton farmers in china this paper examines the role of individual risk attitudes in the decision to adopt a new form of agricultural biotechnology in china i conducted a survey and a field experiment to elicit the risk preferences of chinese farmers who faced the decision of whether to adopt genetically modified bt cotton a decade ago in my analysis i expand the measurement of risk preferences beyond expected utility theory to incorporate prospect theory i find that farmers who are more risk averse or more loss averse adopt bt cotton later farmers who overweight small probabilities adopt bt cotton earlier

a behavioral model of timber supply abstract a dynamic behavioral model of timber supply is developed the diverse motivation of forest owners is recognized and the implications for optimal harvest patterns is explored this model is particularly relevant for the non industrial private forest nipf sector and has possible uses for public forest management properties of the optimal nipf timber supply curve are established and the effects of various taxes are examined to explore a more structured model simulations are conducted based upon data from a typical redwood region the projections provide indicative results for tax and other timber land policies these results are seen to depend crucially on the forms of the landowner s utility function and upon the function relating standing timber to non income outputs of the forest directions for needed empirical research are then indicated

the diffusion of new agricultural technologies the case of crossbred cow technology in tanzania the recent literature on agricultural technology adoption shows that diffusion of new technologies varies significantly across space and time furthermore puzzles exist about why some seemingly profitable technologies are not adopted especially in livestock production we employ a hazard or duration function to explain diffusion of crossbred cow technology in a unique sample of tanzania farmers a farmer s adoption of crossbred technology depends positively on the proximity of his farm to other users on his schooling and on his access to credit and contact with extension agents

community pressure and clean technology in the informal sector an econometric analysis of the adoption of propane by traditional mexican brickmakers abstract in many developing countries the informal sector comprised of low technology unlicensed micro enterprises is a major source of pollution environmental management in this sector is exceptionally challenging though clean technologies offer a means of mitigating the problem to our knowledge there has been no rigorous empirical research on why informal or even small scale firms do and do not adopt them as a first step toward filling this gap this paper presents the results of an econometric analysis of the diffusion of propane among informal traditional brickmakers in cd juarez mexico a leading source of air pollution owing to their reliance on cheap highly polluting fuels such as used tires and scrap wood the two key policy implications of our analysis are that 1 it is possible to successfully promote the adoption of a clean technology by intensely competitive informal firms even when the new technology significantly raises variable costs and 2 community pressure applied by competing firms and private sector local organizations can generate incentives for adoption

ecological economic modeling and valuation of ecosystems abstract we are attempting to integrate ecological and economic modeling and analysis in order to improve our understanding of regional systems assess potential future impacts of various land use development and agricultural policy options and to better assess the value of ecological systems starting with an existing spatially articulated ecosystem model of the patuxent river drainage basin in maryland we are adding modules to endogenize the agricultural components of the system especially the impacts of agricultural practices and crop choice and the process of land use decision making the integrated model will allow us to evaluate the indirect effects over long time horizons of current policy options these effects are almost always ignored in partial analyses although they may be very significant and may reverse many long held assumptions and policy predictions this paper is a progress report on this modeling effort indicating our motivations ideas and plans for completion

investment and abandonment behavior of rural households an empirical investigation this article uses models of irreversible investment under uncertainty to examine the investment and abandonment behavior of poor rural households it considers the decision of ugandan coffee farming households to invest in or abandon coffee trees the observed levels of investment and abandonment are found to be consistent with models of investment that allow for irreversibility uncertainty fixed costs and liquidity constraints the findings highlight the importance of addressing volatility irreversibility fixed costs and liquidity constraints in order to increase households responsiveness to changes in the fundamentals and to enable households to recover from shocks to their capital stock