the adoption of reduced tillage the role of human capital and other variables this paper presents a model of adoption behavior and explains differences econometrically in farmers decisions to adopt reduced tillage practices and in the efficiency of farmers adoption decisions the empirical results obtained from microdata show that the probability of adopting reduced tillage in corn enterprises differs widely across farms and depends on soil characteristics cropping systems and size of farming operation the results also show that farmers schooling enhances the efficiency of the adoption decision

marshall s scale economies using panel data this paper estimates plant level production functions for machinery and high tech industries that allow for scale externalities from other plants in the same industry locally and from the scale or diversity of local economic activity outside the own industry the paper finds that the count of other own industry plants representing a count of local information spillover sources has strong productivity effects in high tech but not machinery industries single plant firms both benefit more from and generate greater external benefits than corporate plants given their greater reliance on external environments on dynamic externalities high tech single plant firms benefit also from the scale of past own industry activity i find little evidence of economies from the diversity or scale of local economic activity outside the own industry

do farmers benefit from participating in specialty markets and cooperatives the case of coffee marketing in costa rica1 historically low prices in the conventional coffee market have caused financial and social hardship among coffee farmers in the face of this crisis specialty markets have attracted the attention of the international donor community these market segments have shown consistent growth over the last decade and exhibit price premiums in international markets therefore if higher prices are passed on to farmers access to specialty markets could help to alleviate the crisis brought on by low prices in the conventional sector the present study attempts to identify the factors that determine farmers participation in specialized markets and whether participation in these markets leads to higher prices for farmers a two stage model is used to analyze farmers marketing decisions and their effect on the prices received this procedure allows us to control for the endogeneity bias introduced by the marketing choice our results indicate that farmers participating in the specialty coffee segment do in fact receive higher prices than those participating in conventional channels additionally we find that participation in cooperatives has a positive impact on the probability that a farmer chooses to grow specialty coffee and analogously on the prices that they receive based on these results it seems that efforts to increase participation in the specialty coffee segment and in cooperatives would help to lessen some of the hardships brought on by low prices in the conventional coffee sector

have coffee producers benefited from the new domestic cherry market evidence using panel data from rwanda the article assesses the effects of the new domestic cherry market on coffee growing households in rwanda using panel data findings from combined first differenced with instrumental variable specification and other estimation methods provide evidence that farmers who sell to the cherry market do not increase their expenditures compared to farmers selling to the traditional parchment market the different time lags in terms of when farmers started selling to the new cherry market may explain the lack of statistically significant differences across the two groups it is possible that farmers will adjust their expenditure patterns in subsequent periods after year over year market trends become more apparent to them

localization economies vertical organization and trade this paper develops a model of regional production networks based on localization economies i consider an industry with two activities one with location specific external economies the other with constant returns under autarky localization economies imply the formation of an industry center agglomeration drives up wages in the center causing the constant returns activity to disperse to outlying regions trade recreates the regional production network on a global scale i apply the model to data from the mexican apparel industry estimation results on mexico s pre and post trade regional apparel wage structure are consistent with localization economies implications for the north american free trade agreement nafta are discussed this abstract was borrowed from another version of this item

participation in the farmer owned reserve program a discrete choice model the food and agriculture act of 1977 initiated a fundamental redirection of u s grain policy previous grain policy revolved around supply control via price supports and marketing quotas or allocations now the active role of grain reserves is emphasized the market is given free rein under normal conditions while grain reserves guard against periods of excessively high or low prices a cornerstone of the new policy is the farmer owned reserve for program the for is designed to stabilize grain prices and contribute to food security by encouraging farmers to hold more grain in storage than they would otherwise because the program is voluntary it is important to understand what motivates participation in the for it is also important to quantify at least partially the decision making process if policy makers are to forecast farmer responsiveness to policy actions in recent studies addressing this question little attention has been given to statistical modelling of individual decision making meyers and ryan meyers jolly and ryan burnstein this paper describes an empirical model of the for participation decision using a theoretical choice model and discrete econometrics the major provisions of the for are first outlined next a theoretical choice model based on a stochastic utility function is presented crosssection data for corn and wheat producers gathered by a subcommittee of north central regional project 152 nc 152 are used to estimate empirical models of the decision making process the paper concludes with pertinent policy implications the farmer owned grain reserve

protecting forests biodiversity and the climate predicting policy impact to improve policy choice p olicies must balance forest conservation s local costs with its benefits local to global in terms of biodiversity the mitigation of climate change and other eco services such as water quality the trade offs with development vary across forest locations we argue that considering location in three ways helps to predict policy impact and improve policy choice i policy impacts vary by location because baseline deforestation varies with characteristics market distances slopes soils etc of loca tions in a landscape ii different mixes of political economic pressures drive the location of different policies and iii policies can trigger second order or spillover effects likely to differ by location we provide empirical evidence that suggests the importance of all three considerations by reviewing high quality evaluations of the impact of conservation and development on forest impacts of well enforced conservation rise with private clearing pressure supporting i protection types e g federal state dif fer in locations and thus in impacts supporting ii differences in development process explain differ ent signs for spillovers supporting iii

economic vs non material incentives for participation in an in kind payments for ecosystem services program in bolivia abstract this study examines the motivations that drive participation in a compensation program for environmental conservation in bolivia previous research on payments programs suggests that institutions that appeal to both economic and non material incentives should be encouraged this program attempts such a strategy offering in kind compensation for conservation while simultaneously attempting to engage with environmental values and traditional social norms i take advantage of a comprehensive household survey conducted prior to the offer of the program and employ means comparison tests and multi level regression analysis to compare those who chose to participate with those who did not my research examines whether motivations for participating in this program reflected purely financial calculations regarding the costs and benefits of the program or whether non financial motivations such as environmental or social beliefs and norms played a role as well i find evidence that the program s effort to engage with social motivations was successful and that social factors not financial incentives alone affect participation in the program findings also suggest that environmental values did not play a very large role and that the financial determinants of participation are related mainly to prohibitive costs or barriers to entry rather than the size of anticipated benefits

central bank independence and public debt policy the various proposals for the institutional design of the european monetary union have drawn fresh attention to the link between monetary and public debt policies this paper explores the strategic interaction between fiscal authorities setting public debt and the central bank controlling monetary policy in the absence of political distortions an optimally designed conservative independent central bank is sufficient to establish the second best in the presence of political distortions or with coordination of monetary and fiscal policy however also a debt target is needed

economies of scope and economies of agglomeration abstract agglomeration economies are economies external to the firm and plant but internal to a particular location in this paper the notion of agglomeration economies is formally investigated the implications of the concept for urban structure and industrial organization are then traced under specified considerations weak economies of agglomeration as defined in this paper are shown to be necessary for the existence of an urban area

geography industrial organization and agglomeration this paper makes two contributions to the empirical literature on agglomeration economies first the paper uses a unique and rich database in conjunction with mapping software to measure the geographic extent of agglomerative externalities previous papers have been forced to assume that agglomeration economies are club goods that operate at a metropolitan scale second the paper tests for the existence of organizational agglomeration economies of the kind studied qualitatively by saxenian 1994 this is a potentially important source of increasing returns that previous empirical work has not considered results indicate that localization economies attenuate rapidly and that industrial organization affects the benefits of agglomeration

rising trade costs agglomeration and trade with endogenous transaction costs while transport costs have fallen the empirical evidence also points at rising total trade costs in a model of industry location with endogenous transaction costs that seeks to replicate features from the machinery industry we show how and under which conditions a decline in transport costs can lead to an increase in the total cost of trade the subtle relationship between endogenous transport costs and the sensitivity of trade

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

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

contract duration and relationship specific investments empirical evidence from coal markets this paper examines the importance of specific relationship investments in determining the duration of coal contracts negotiated between coal suppliers and electric utilities data for 277 coal contracts are used to perform the analysis the results provide strong support for the view that buyers and sellers make longer commitments to the terms of future trade at the contract execution stage and rely less on repeated bargaining when relationship specific investments are more important

modeling technology adoption in developing countries an analysis of technology adoption decisions by poor farmers is provided some possible empirical models for studying technology adoption are reviewed the issue of theoretical consistency is dealt with in terms of the costs of such consistency measured in data needs and model complexity and the benefits measured in terms of understanding the micro economic foundations of adoption

efficiency of payments for environmental services equity and additionality in a case study from a biosphere reserve in chiapas mexico payments for environmental services pes have been claimed as a more efficient way of accomplishing conservation and development goals than other indirect strategies reaching their optimum when the buyer pays the opportunity costs of the foregone benefits different inefficient situations have been described like lack of additionality where payments are given for practices that would have been adopted anyway trade offs between efficiency and equity of pes have usually emerged as well in this paper we assess the equity additionality and stakeholders perceptions of a pes scheme in a mexican community inside a biosphere reserve we applied structured interviews to all adults a total of 66 people from 31 households our results show a dual response in equity and additionality depending on land tenure pes have an egalitarian effect within landowners and landless groups but it broadens the gap between them additionality is low for landowners and high for the landless people in the community even though the former are the ones with full decision over the land although the scheme does not seem efficient under the classical pes paradigm it is perceived as a reward reinforcing conservation attitudes even though most of the interviewees claim it to be insufficient

agglomeration opportunism and the organization of production abstract recent economic analysis of outsourcing has emphasized its international dimension in contrast this paper focuses on local outsourcing the paper specifies and solves a model where the organization of production vertically integrated or not and the location of production agglomerated or not are jointly determined the paper shows that agglomeration reduces opportunism a thick market effect and so serves as a substitute for integration this force will lead firms to agglomerate the paper also shows that the normative properties of equilibrium with local outsourcing are not as clear cut as for international outsourcing since local agglomeration is achieved at the cost of congestion local markets may be too thick which would not be the case for an increase in the thickness of a world market finally the many changes in economic and social circumstance that have been labeled globalization do not impact only vertically integrated firms they also impact cities and industry clusters to the extent that agglomeration is a substitute for vertical integration

competition by choice the effect of consumer search on firm location decisions this paper relates firm location choice and consumer search firms that cluster together attract consumers by facilitating price comparison but clustering increases the intensity of local competition the author constructs a simple model which shows that firms may choose head on competition by locating together under reasonable conditions this is the only equilibrium outcome copyright 1990 by american economic association

conditional cash transfers and payments for environmental services a conceptual framework for explaining and judging differences in outcomes we develop a conceptual framework elucidating the main determinants of the impact of conditional cash transfer cct and payments for environmental services pes programs using a simple multi agent model and evaluations of existing programs we show that 1 the share of the population who would meet the program s conditions in the absence of payments is a powerful predictor of program efficiency and that 2 program efficiency is eroded by selection bias people who already meet conditions self select into the programs at higher rates than others we then discuss possibilities for increasing efficiency and criteria for evaluating and choosing between ccts pes or other policy instruments

determinants of smallholder commercial tree cultivation abstract this article contains a discussion of how output prices tenure information credit technology government policies and labor availability affect smallholder commercial tree cultivation output prices play the key role in smallholder commercial tree cultivation even in the face of insecure tenure output prices however are a necessary but not a sufficient condition to induce smallholders to undertake commercial fuelwood cultivation

paying for environmental services an analysis of participation in costa rica s psa program summary costa rica has long been a leader among developing countries in the design of and experimentation with innovative environmental programs since 1997 costa rica s pagos de servicios ambientales payments for environmental services program has provided payments to more than 4 400 farmers and forest owners for reforestation forest conservation and sustainable forest management activities econometric analysis of a survey of farmers and forest owners including both psa participants and nonparticipants shows that farm size human capital and household economic factors and information variables significantly influence participation in psa program alternatives large farmers and forest owners are disproportionately represented among program participants

payments for environmental services in costa rica costa rica pioneered the use of the payments for environmental services pes approach in developing countries by establishing a formal country wide program of payments the psa program the psa program has worked hard to develop mechanisms to charge the users of environmental services for the services they receive it has made substantial progress in charging water users and more limited progress in charging biodiversity and carbon sequestration users because of the way it makes payments to service providers using approaches largely inherited from earlier programs however the psa program has considerable room for improvement in the efficiency with which it generates environmental services with experience many of these weaknesses are being gradually corrected as the psa program evolves towards a much more targeted and differentiated program an important lesson is the need to be flexible and to adapt to lessons learned and to changing circumstances

conservation versus equity can payments for environmental services achieve both this paper investigates the trade off between conservation and equity considerations in the use of payments for environmental services pes that implicitly incorporate different distributive justice principles using a public good experiment with heterogeneous participants we compare the effects on additional area conserved and distribution of earnings of two pes schemes an equal payment and a payment based on rawls distributional principle which we refer to as maxi min payment scheme the main findings of the framed field experiment conducted in jambi province indonesia indicate that the introduction of a maxi min pes scheme can function as a multi purpose instrument it realigns the income distribution in favor of low endowed participants and does not necessarily need to be compromised by lower environmental additionality at the group level

education and innovation adoption in agriculture evidence from hybrid rice in china this paper uses the diffusion of f1 hybrid rice as a case for examining the effects of education on the adoption of new technology in china a simple behavioral model that treats the adoption of hybrid rice as a portfolio selection problem is presented the implications of the model are tested with farm level data collected from a sample of 500 households in hunan province the results from a dichotomous probit model and a two limit tobit model are consistent with the hypothesis that education has a positive impact on the adoption of new technology

between ostrom and nordhaus the research landscape of sustainability economics abstract we survey the emerging research area of sustainability economics through a quantitative full text analysis of peer reviewed journal publications from 1987 to 2013 to identify relevant contributions we draw on existing definitions of sustainability economics for a keyword based identification strategy a combined focus on a the human nature relationship b the long term uncertain future c normative orientation towards sustainability and d economic analysis our analysis of a random subsample of 343 relevant papers reveals that i sustainability economics is a rapidly developing research area ii while theoretical contributions shaped the area in earlier years applied work now constitutes the largest share of contributions iii the research landscape can be clustered into eleven research clusters these range from participatory governance of social ecological systems associated with the work of elinor ostrom to questions of intertemporal allocation and distribution applied to climate economics associated with the work of william nordhaus iv the research area is broad in scope and heterogeneous and there is relatively little interaction between important clusters v relevant contributions are published in more than 100 journals ten journals publish half of all contributions led by ecological economics and 40 appear in non economics journals underscoring the importance of interdisciplinary dialogue

poor household participation in payments for environmental services lessons from the silvopastoral project in quindio colombia as the use of payments for environmental services pes approaches in developing countries has grown concern has arisen over the ability of poorer households to participate this paper uses data from a pes project implemented in quindio colombia to examine the extent to which poorer households that are eligible to participate are in fact able to do so the project provides a strong test of the ability of poorer households to participate in a pes program as it required participants to make substantial and complex land use changes the results show that poorer households are in fact able to participate at levels that are broadly similar to those of better off households moreover their participation was not limited to the simpler least expensive options transaction costs may be greater obstacles to the participation of poorer households than household specific constraints

why do farmers join payments for ecosystem services pes schemes an assessment of pes water scheme participation in brazil payments for ecosystem services pes have become a popular instrument in the last decades and this growing trend is also clearly evident in brazil however challenges related to implementation of these schemes are often underestimated any guarantee that a payment will secure or provide such a service is subject not only to underlying ecological uncertainties but also to those entailed by the kinds of social interaction that are inherent to policy implementation it is argued that the objectives proposed with these instruments can only be attained by ensuring a wide participation of land users this article advances this topic reporting and discussing evidence on farmer s reasons to participate in three pes water schemes in brazil using a combination of qualitative and quantitative research approaches results indicate that the diverging opinions regarding how ecosystem services are generated or secured decentralized governance structures and the involvement of representative bodies in scheme design and implementation are important factors to consider furthermore access to information and general environmental concern were found to be important variables to explain the propensity of farmers to participate this generates serious policy implications for developing consistent communication and consultation strategies with scheme beneficiaries

the fable of fisher body abstract general motors s gm s acquisition of fisher body is the classic example of market failure in the literature on contracts and the theory of the firm according to the standard account in 1926 gm merged vertically with fisher body a maker of auto bodies because of concerns over transaction specific investment and contractual holdup that account exhibits errors of historical fact and interpretation general motors acquired a 60 percent interest in fisher body in 1919 moreover the contractual arrangements and working relationship prior to the 1926 merger exhibited trust rather than opportunism fisher body s production technology did not exhibit asset specificity the merger reflected economic considerations specific to that time not some immutable market failure we demonstrate that vertical integration was directed at improving coordination of production and inventories assuring gm of adequate supplies of auto bodies and providing gm with access to the executive talents of the fisher bro

investigating fishers preferences for the design of marine payments for environmental services schemes we determine the effects of various management restrictions on adoption rates of marine payments for environmental services pes schemes choice experiments are used in order to determine how fisher participation rates change under different marine pes programme designs various designs with differing restriction rates show different rates of adoption however fishers show a high utility loss associated with any move away from the current management situation irrespective of restriction levels this indicates that pes scheme costs may be high and creating an enabling environment could be important to reducing perceived losses as could investment into conditional in kind compensation mechanisms the paper also shows choice experiments to be a useful tool in marine pes design

creating holdup through vertical integration fisher body revisited abstract general motors s gm s 1926 acquisition of fisher body has long served as a cornerstone of hold up arguments for vertical integration this paper utilizes primary historical evidence to make three related claims first it shows that gm s initial investment in fisher body occurred primarily to gain access to the fisher brothers specialized human assets second it shows that holdup was not the cause of gm s purchase of fisher body instead the primary factors leading to vertical integration were gm management s fears over the fisher brothers impending departure coupled with problems of financing new body plants finally i show that while holdup was not an issue prior to integration the fisher brothers successfully held up gm after they became employees far from reducing opportunistic behavior vertical integration increased gm s vulnerability to rent seeking behavior based in human asset specificity

estimating supply response in the presence of farm programs previous empirical research on crop supply response has given insufficient attention to the fundamentally different nature of supply response under farm programs versus competitive markets a simple theoretical model is presented which highlights the program participation option in the farmer s acreage allocation decision the model also provides the basis for different expected supply elasticities under free market and farm program regimes for corn and soybeans econometric supply estimation for corn belt states for 1948 80 using a temporally disaggregated approach confirms a greater supply elasticity for corn and a lower supply elasticity for soybeans under acreage restricting feed grain programs

the economic valuation of nature a question of justice while many of the concerns over the economic valuation of nature have gained broad exposure justice concerns remain largely peripheral within both scholarly debate and actual valuation exercises the emphasis is most often on reconciling cultural and monetary valuation increasingly as the valuation of nature gains momentum proponents of the trend seek to relieve apprehensions by suggesting that economic valuation is entirely compatible with intrinsic and esthetic values this attempt to mollify skeptics however misses the mark regardless of whether or not nature may be valued simultaneously in cultural and economic terms the social and environmental justice implications of monetary valuation remain the purpose of this commentary is to clarify that much of the resistance to the economic valuation of nature is motivated by these justice concerns and that reassurances about the cultural value of nature do little to quell them several of the justice reasons to remain cautious of the economic valuation of nature are also elaborated

performance of an agro forestry based payments for environmental services project in mozambique a household level analysis there has been a paucity of research on the impacts of small scale payments for environmental services pes projects in developing countries the aim of this paper is to evaluate the household level impacts of a small scale agro forestry based carbon sequestration project in rural mozambique in 2006 questionnaire based interviews were conducted quarterly of 290 randomly selected households in the buffer zone of the gorongosa national park in mozambique we used the propensity score matching technique to assess the pes project impacts on household cash income consumption expenditure forest resource use and crop yields we found that in contrast to nonparticipant households pes participant households earned more cash income incurred more consumption expenditure collected less forest products and harvested lower quantities of agriculture crops in addition we found through decomposition analysis that there was a differential in pes income both male headed and high income households were being favoured as project benefit recipients future pes projects should focus on a payment scheme that can better ensure the benefit to all the participant households and also pay extra attention on the benefits distribution to the vulnerable households

globalization outsourcing and wage inequality there is considerable debate over whether international trade has contributed to the declining economic fortunes of less skilled workers one issue that has become lost in the current discussion is how firms respond to import competition and how these responses in turn are transmitted to the labor market in previous work we have argued that outsourcing by which we mean the import of intermediate inputs by domestic firms has contributed to an increase in the relative demand for skilled labor in the united states if firms respond to import competition from low wage countries by moving non skill intensive activities abroad then trade will shift employment towards skilled workers within industries in this paper we extend our previous work by combining new import data from the revised nber trade database with disaggregated data on input purchases from the census of manufactures we construct industry by industry estimates of outsourcing for the period 1972 1990 and reexamine whether outsourcing has contributed to an increase in relative demand for skilled labor our main finding is that outsourcing can account for 31 51 of the increase in the relative demand for skilled labor that occurred in u s manufacturing industries during the 1980s compared to our previous estimate of 15 33 this abstract was borrowed from another version of this item

the effectiveness of payments for environmental services we adopt a theory based approach to synthesize research on the effectiveness of payments for environmental services in achieving environmental objectives and socio economic co benefits in varying contexts our theory of change builds on established conceptual models of impact pathways and highlights the role of 1 contextual dimensions e g political institutional and socio economic conditions spatial heterogeneity in environmental service values and provision costs and interactions with pre existing policies and 2 scheme design e g payment type and level contract length targeting and differentiation of payments in determining environmental and socio economic outcomes to shed light on the overall effectiveness of payment schemes and its determinants we review counterfactual based empirical evaluations comparative analyses of case studies and meta analyses our review suggests that program effectiveness often lags behind the expectations of early theorists however we also find that theory has advanced sufficiently to identify common reasons for why payment schemes fail or succeed moreover payment schemes are often rolled out along with other policy instruments in so called policy mixes advances in theory and evaluation research are needed to improve our understanding of how such policy mixes interact with the targeted social ecological systems 2017

present bias predicts participation in payments for environmental services evidence from a behavioral experiment in uganda farmers are necessary agents in global efforts to conserve the environment now that croplands and pastures together constitute the largest terrestrial system on earth covering some 48 of ice free land surface whereas standard economic models predict that farmers will participate in conservation programs so long as they are profitable empirical findings from behavioral economics point to a number of normally unobservable preferences that may influence the decision making process this study tests for the first time whether heterogeneity in behavioral preferences correlates with decisions to participate in payments for environmental services pes programs we elicit individual trust and time preferences using economic experiments and link resulting measures to household survey data and participation decisions in a ugandan pes program we find that farmers who exhibit a preference for proximate gains present biased preferences are 47 7 more likely to participate in the program than those who show time consistent or future biased preferences this result has implications for ongoing and planned pes programs involving farmers particularly in africa by highlighting a potential relationship between payment timing and participation and further validates the use of behavioral experiments in explaining real world decisions

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

tenure constraints and carbon forestry in africa our analysis shows that landowners with customary tenure in africa can be efficient providers of carbon forestry if tree planting helps secure their permanent claims to the land if the farmer s tree planting can reduce the threat of eviction the amount of land allocated to carbon forestry may be greater or lesser than under private ownership but it is always more than if tenure security is completely absent our results support the view that carbon forestry schemes should accommodate traditional african customary tenure systems and if designed successfully can both promote carbon forestry and benefit the poor

urban diversity and economic growth at the risk of some simplification it is possible to identify four periods of intense study of cities by economists each of these has led to an increased understanding of the economics of urban areas and the unique role played by cities in the modem economy the first of these periods occurred in the decade after world war i only about ten years after the truck revolutionized the transport of goods within urban areas this period included the first systematic empirical analysis of the forces affecting the location of firms and households within cities robert murray haig 1926 and a number of other microeconomists at columbia analyzed the spatial pattems of manufacturing activity in lower manhattan and in the rest of new york city haig jmd his colleagues devoted considerable attention to where things belong in an urban area p 402 providing the first systematic economic analysis of urban spatial structure for example they analyzed the garment industry concluding that it was destined by nature to disperse north of 14th street and predicting that it would follow the estabhshed spatial pattem of the cooperage barrelmaking industry standardization in size and quality of barrels had meant that identical barrels could be made throughout the new york metropolitan area even in new jersey and the introduction of the truck meant that they could be transported cheaply throughout the region and exported the second of these periods though not in chronological order began in the mid 1960s it formalized many of the insights about location incentives within urban areas which had been uncovered a half century before mixed them with the logic of heinrich von thunen s 1826 ancient theories about agricultural crops and land values and applied them to the hotisehold sector the works of william alonso 1964

product differences and prices abstract under assumptions following hotelling s 1929 paper stability in competition the possibility of constructing an example in which equilibrium prices exist everywhere and the two merchants display tendencies to agglomerate is ruled out

outsourcing in a global economy we study the determinants of the location of subcontracted activity in a general equilibrium model of outsourcing and trade we model outsourcing as an activity that requires search for a partner and relationship specific investments that are governed by incomplete contracts the extent of international outsourcing depends inter alia on the thickness of the domestic and foreign market for input suppliers the relative cost of searching in each market the relative cost of customizing inputs and the nature of the contracting environment in each country

payments for environmental services in watersheds insights from a comparative study of three cases in central america we have compared three cases of payments for water related environmental services pes in central america in terms of socioeconomic background opportunity costs of forest conservation and stakeholders perceptions of the conditions of water resources and other issues we found that in general the opportunity costs are larger than the amounts paid which apparently contradicts the economic foundation of pes schemes and suggests that the role of intangibles is important in inducing participation the results also show that trade offs between different environmental and social goals are likely to emerge in pes schemes posing some doubts as to their ability to be multipurpose instruments for environmental improvement and rural development we also found that pes schemes may work as a conflict resolution instrument facilitating downstream upstream problem solving though at the same time they might introduce changes in social perceptions of property rights