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

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 worst case efficiency of cost sharing methods in resource allocation games resource allocation problems play a key role in many applications including traffic networks telecommunication networks and economics in most applications the allocation of resources is determined by a finite number of independent players each optimizing an individual objective function an important question in all these applications is the degree of suboptimality caused by selfish resource allocation we consider the worst case efficiency of cost sharing methods in resource allocation games in terms of the ratio of the minimum guaranteed surplus of a nash equilibrium and the maximal surplus our main technical result is an upper bound on the efficiency loss that depends on the class of allowable cost functions and the class of allowable cost sharing methods we demonstrate the power of this bound by evaluating the worst case efficiency loss for three well known cost sharing methods incremental cost sharing marginal cost pricing and average cost sharing

risk and insurance in a rural credit market an empirical investigation in northern nigeria credit contracts play a direct role in pooling risk between households in northern nigeria repayments owed by borrowers depend on realizations of random shocks by both borrowers and lenders the paper develops two models of state contingent loans the first is a competitive equilibrium in perfectly enforceable contracts the second permits imperfect information and equilibrium default estimates of both models indicate that quantitatively important state contingent payments are embedded in these loan transactions but that a fully efficient risk pooling equilibrium is not achieved the research is based on a year long survey in zaria nigeria conducted by the author

the formation of risk sharing networks this paper examines the formation of risk sharing networks in the rural philippines we find that geographic proximity possibly correlated with kinship is a major determinant of mutual insurance links among villagers age and wealth differences also play an important role in contrast income correlation and differences in occupation are not determinants of network links reported network links have a strong effect on subsequent gifts and loans gifts between network partners are found to respond to shocks and to differences in health status from this we conclude that intra village mutual insurance links are largely determined by social and geographical proximity and are only weakly the result of purposeful diversification of income risk the paper also makes a methodological contribution to the estimation of dyadic models

does africa need a rotten kin theorem experimental evidence from village economies this paper measures the economic impact of social pressure to share income with kin and neighbors in rural kenyan villages the authors conduct a lab experiment in which they randomly vary the observability of investment returns the goal is to test whether subjects reduce their income in order to keep it hidden the analysis finds that women adopt an investment strategy that conceals the size of their initial endowment in the experiment although that strategy reduces their expected earnings this effect is largest among women with relatives attending the experiment parameter estimates suggest that women behave as though they expect to be pressured to share four percent of their observable income with others and substantially more when close kin can observe income directly although this paper provides experimental evidence from a single african country observational studies suggest that similar pressure from kin may be prevalent in many rural areas throughout sub saharan africa

kinship and financial networks formal financial access and risk reduction kinship networks are beneficial for smoothing consumption and investment but the channels are not well understood we study the financing devices used for consumption and investment by thai households households that are connected to banks achieve significantly better consumption smoothing than unconnected households indirect connections via inter household borrowing are as effective as direct borrowing investment appears to be facilitated by kinship households with kin in the village display reduced sensitivity of investment to income while connections to banks do not significantly reduce sensitivity kin may act as implicit collateral permitting borrowing that would violate repayment constraints in its absence

the role of roscas lumpy durables or event insurance abstract the stylised representation of roscas in recent theoretical work as a device driven by impatience for lumpy consumer durables misses the important insurance role of this pervasive informal financial institution in the developing world that insurance role explains why roscas with concurrent bidding are the dominant means of determining the sequence and pricing of allocations in roscas so structured the recipient and the implied interest rate for each period s allotment are determined by competitive bids at the time of distribution we use an example of an actual bidding rosca to demonstrate the extent of unpredictable needs for funds as reflected in the volatility of interest rates implicit in winning bids

group based funeral insurance in ethiopia and tanzania a funeral is a costly occasion this paper studies indigenous insurance institutions developed to cope with the high costs of funerals based on evidence from rural areas in tanzania and ethiopia these institutions are based on well defined rules and regulations often offering premium based insurance for funeral expenses increasingly they are also offering other forms of insurance and credit to cope with hardship the paper argues that the characteristics and inclusiveness of these institutions make them well placed as models to broaden insurance provision and other developmental activities in these communities the history of these institutions is characterised by a resistance to attempts of political capture and helps to understand their apparent resistance to engage more broadly with ngos and government agencies as a result any attempt to expand their activities will have to be done cautiously

a nonparametric elicitation of the equity efficiency trade off in cost utility analysis we performed an empirical elicitation of the equity efficiency trade off in cost utility analysis using the rank dependent quality adjusted life year qaly model a model that includes as special cases many of the social welfare functions that have been proposed in the literature our elicitation method corrects for utility curvature and therefore our estimated equity weights are not affected by diminishing marginal utility we observed a preference for equality in the allocation of health the data suggest that the elicited equity weights were jointly determined by preferences for equality and by insensitivity to group size a procedure is proposed to correct the equity weights for insensitivity to group size finally we give an illustration how our method can be implemented in health policy

pretending to be poor borrowing to escape forced solidarity in cameroon abstractfrom field observations of credit cooperatives in cameroon we find that 19 of the loans taken are fully collateralized by savings held in the same institutions this behavior is costly to the borrower as it represents a net interest payment of about 24 per year while traditional explanations may partly explain this behavior interviews with members of the cooperatives suggest the following new rationale members resort to borrowing to signal to friends and relatives that they are poor and do not have savings available by doing so they can avoid requests for financial help we develop a signaling model to analyze the conditions under which this behavior is an equilibrium outcome

descent rules and strategic transfers evidence from matrilineal groups in ghana abstract traditional descent systems can roughly be divided into patrilineal and matrilineal in the latter a man s heir is not his own child but rather his sister s son the paper examines the implications of this social norm for the pattern of inter vivos transfers using household level data from rural ghana where the largest ethnic group is traditionally matrilineal in particular it tests the predictions of a model of strategic behavior according to which children should respond to the threat of disinheritance by increasing transfers to their parents during lifetime to induce a donation of land before the default matrilineal inheritance is enforced i find that the credibility of customary norms enforcement as proxied by the presence of a nephew in the father s household significantly increases the probability of receiving transfers from children for akans but not for the other groups the effect is specific to nephews and not to other co resident boys this pattern of behavior can affect asset accumulation decisions across generations

group formation in risk sharing arrangements we study informal insurance within communities explicitly recognizing the possibility that subgroups of individuals may destabilize insurance arrangements among the larger group we therefore consider self enforcing risk sharing agreements that are robust not only to single person deviations but also to potential deviations by subgroups however such deviations must be credible in the sense that the subgroup must pass exactly the same test that we apply to the entire group it must itself employ some self enforcing risk sharing agreement we observe that the stability of subgroups is inimical to the stability of the group as a whole two surprising consequences of this analysis are that stable groups have uniformly bounded size a result in sharp contrast to the individual deviation problem and that the degree of risk sharing in a community is generally non monotonic in the level of uncertainty or need for insurance in the community

kinship incentives and evolution we analyze how family ties affect incentives with focus on the strategic interaction between two mutually altruistic siblings the siblings exert effort to produce output under uncertainty and they may transfer output to each other with equally altruistic siblings their equilibrium effort is non monotonic in the common degree of altruism and it depends on the harshness of the environment we define a notion of local evolutionary stability of degrees of sibling altruism and show that this degree is lower than the kinship relatedness factor numerical simulations show how family ties vary with the environment and how this a ects economic outcomes

a dark side of social capital kinship consumption and savings abstract we explore whether traditional sharing norms in kinship networks affect consumption and accumulation decisions of poor black households in kwazulu natal south africa using a proxy for the number of family dependents our results are consistent with the interpretation that households try to evade their sharing obligations by i accumulating durables that are non sharable at the expense of durables that may be shared and ii reducing savings in liquid assets by attenuating accumulation incentives kinship sharing may come at the expense of income growth if so a culturally induced poverty trap can possibly eventuate we demonstrate tentative evidence that more extensive kinship networks are associated with lower incomes

tenure security resource endowments and tree growing evidence from the amhara region of ethiopia we analyze roles of tenure insecurity and household endowments in explaining tree growing in ethiopia where farmers cannot sell or mortgage land and factor markets are imperfect unlike most other studies we use panel data and examine determinants of the decision and intensity of tree growing unlike other studies we compare the decision to keep trees and the decision to plant in the recent past the results suggest that land tenure insecurity influences the decision to grow trees but not the number of trees households grow household endowments time and location also explain tree growing by farmers

the impact of kinship networks on the adoption of risk mitigating strategies in ethiopia the adoption of certain farm management practices such as tree planting and soil and water conservation can reduce exposure to weather shocks however in many countries the adoption of such risk mitigating measures is far from complete we explore how risk sharing networks in the form of kinship characterized by the moral imperative of within group sharing affects the adoption of risk mitigating activities in rural ethiopia we find suggestive evidence that compulsory sharing invites free riding and attenuates incentives for self protection against weather shocks we also find evidence of the existence of a possible substitution effect between credit and social networks

does adaptation to climate change provide food security a micro perspective from ethiopia we examine the driving forces behind farmers decisions to adapt to climate change and the impact of adaptation on farmers food production we investigate whether there are differences in the food production functions of farm households that adapted and those that did not adapt we estimate a simultaneous equations model with endogenous switching to account for the heterogeneity in the decision to adapt or not and for unobservable characteristics of farmers and their farm we compare the expected food production under the actual and counterfactual cases that the farm household adapted or not to climate change we find that the group of farm households that adapted has systematically different characteristics than the group of farm households that did not adapt the relationship between production and average temperature is inverted u shaped for farm households that adapted while it is u shaped for farm households that did not adapt and vice versa in the case of precipitation we find that adaptation increases food production however the impact of adaptation on food production is smaller for the farm households that actually did adapt than for the farm households that did not adapt in the counterfactual case that they adapted

imperfect commitment altruism and the family evidence from transfer behavior in low income rural areas in this paper we examine empirically whether risk pooling is more advantageous among altruistic compared to selfish agents in a framework where individuals cannot make binding commitments in particular we incorporate altuism into a model of risk sharing under imperfect commitment and use simulation methods to establish tests of the roles of both altruism and commitment problems in determining the extent of insurance and the intertemporal movements in interhousehold transfers the tests are carried out using three panel data sets from two countries of rural south asia that provide detailed information on transfers and enable the measurement of income shocks the estimates provide strong support for the notion that imperfect commitment substantially constrains informal transfer arrangements whether kin based or not but also provide evidence that altruism plays an important role in ameliorating commitment constraints and thus in increasing the gains from income pooling

mitigating climate change by planting trees the transaction costs trap land use change and forestry projects are considered a low cost option for addressing climate change mitigation in canada afforestation is targeted to sequester enough carbon to meet one fifth of its international obligations and at lower cost than emissions reduction we examine economic aspects of the institutions and incentives needed to encourage landowners in canada to adopt tree planting on a large scale based on data from a survey of landowners the transaction costs of getting landowners to convert their land from agriculture to plantation forests appear to be a significant obstacle possibly increasing the costs of afforestation projects beyond what conventional economic analysis suggests