characterizing cross country consumption correlations general equilibrium models of international fluctuations that assume complete asset markets predict that consumption will be highly correlated across countries while the data display correlations that are rather low it has become common to characterize this empirical regularity by noting that cross country consumption correlations tend to be lower than corresponding output correlations this note reconsiders that charac terization and demonstrates that it is not particularly robust it also documents a related regularity that is more pervasive consumption fluctuations are more highly correlated with domestic production than with world output this provides an alternative standard for evaluating models of international fluctuations

indirect effects of an aid program how do cash transfers affect ineligibles consumption cash transfers to eligible households indirectly increase the consumption of ineligible households living in the same villages this effect operates through insurance and credit markets ineligible households benefit from the transfers by receiving more gifts and loans and by reducing their savings thus the transfers benefit the local economy at large looking only at the effect on the treated underestimates the impact one should analyze the effects of this class of programs on the entire local economy rather than on the treated only and use a village level randomization rather than selecting treatment and control subjects from the same community

risk sharing by households within and across regions and industries abstract cochrane 1991 journal of political economy 99 957 976 and mace 1991 journal of political economy 99 928 956 test if risk sharing across households is complete in the sense that household consumption moves one for one with aggregate consumption in their studies the source of income risk is idiosyncratic and agents can share risk across the entire economy using a sample of households from the panel study on income dynamics psid we explore whether households share the risk associated with their industries and regions across households in other regions and industries we find that a large fraction of risk faced by households is not shared across regions and industries

precautionary wealth accumulation evidence from canadian microdata this paper estimates the effect of labour income uncertainty on wealth accumulation using two data sources wealth information is obtained from the master files of the new canadian survey of financial security 1999 sfs labour income risk proxies are constucted by industry using the canadian survey of labour and income dynamics slid between 1996 and 2001 the empirical results suggest the presence of a strong precautionary saving motive among canadian households for broad definitions of wealth furthermore consistent with the buffer stock saving model the level of precautionary funds significantly increases when households face liquidity constraints ce texte calcule l effet de l incertitude du revenu de travail sur l accumulation de la richesse a l aide de deux sources de donnees les donnees sur la richesse sont tirees des resultats de l enquete sur la securite financiere esf de 1999 les coefficients de risque attaches aux diverses industries sont developpes a partir des resultats de l enquete sur la dynamique du travail et du revenu edtr entre 1996 et 2001 les resultats empiriques suggerent la presence d une forte motivation des menages canadiens aepargner aux fins de precaution si l on accepte des definitions assez comprehensives de la richesse de plus d une maniere qui correspond au modele d epargne pour stockage tampon le niveau des fonds aux fins de precaution s accroit de maniere significative a proportion que les menages font face a des contraintes de liquidite

informal insurance arrangements with limited commitment theory and evidence from village economies recent work on consumption allocations in village economies finds that idiosyncratic variation in consumption is systematically related to idiosyncratic variation in income thus rejecting the hypothesis of full risk pooling we attempt to explain these observations by adding limited commitment as an impediment to risk pooling we provide a general dynamic model and completely characterise efficient informal insurance arrangements constrained by limited commitment and test the model using data from three indian villages we find that the model can fully explain the dynamic response of consumption to income but that it fails to explain the distribution of consumption across households

temporary migration and endogenous risk sharing in village india when people can self insure via migration they may have less need for informal risk sharing at the same time informal insurance may reduce the need to migrate to understand the joint determinat

is consumption smooth at the cost of volatile leisure an investigation of rural india this study examines the institutions in rural india that enable households to insure against unanticipated idiosyncratic shocks to income using a decentralized general equilibrium model it tests for consumption and leisure insurance against unanticipated income shocks it is found that differential access to markets particularly financial markets force villagers to differ in their response to similar shocks medium and large farmers have unrestricted access to credit markets and are unaffected by unanticipated changes in household income the small farmers are excluded from credit markets however some of the small farmers are able to insure consumption against unanticipated income shocks through compensating changes in labour market participation and reducing own farm work

precautionary savers with ricardian propensities in his seminal 1974 paper barro noted that ricardian equivalence may fail if agents face undiversifiable idiosyncratic risk and governments finance tax rebates with higher future tax rates 5 higher tax rates reduce the dispersion of future after tax income decrease the precautionary demand for savings and hence tend to stimulate present consumption barro concluded however that the stimulus to consumption would be minor and would likely be offset by induced reductions in future labor income the recent revival of interest in the precautionary savings motive has refocused attention on this tax insurance effect tie 2 8 24 27 in particular two highly influential papers one by barsky mankiw and zeldes 6 and the other by kimball and mankiw 19 argue that the tax insurance effect generates consumption responses roughly equivalent to those obtained from keynesian models where agents ignore future tax liabilities entirely although the existence of a precautionary demand for savings and by implication a taxinsurance effect has received strong empirical support 9 15 21 the magnitude of the effect remains largely unknown the two most difficult empirical issues involve quantifying the degree of uninsured idiosyncratic risk faced by typical agents and determining the appropriate form and shape of agents utility functions on these issues the profession is far from a consensus studies from the labor economics literature 1 17 suggest idiosyncratic risk may be large and persistent whereas a recent paper by heaton and lucas 16 finds idiosyncratic risk to be small and largely transitory similarly the vast literature surrounding the equity premium puzzle highlights the profession s lack of consensus over the degree of risk aversion exhibited by typical agents in this paper i circumvent some of these controversial issues by extending barsky mankiw and zeldes model to include an explicit labor supply decision the introduction of a labor supply decision allows me to bring evidence from the literature on optimal income taxation 22 25 and the literature on the welfare cost of taxation 3 4 7 to bear on these issues the idea is simple under the conditions that make the tax insurance effect large i e very risky income distributions and a high degree of risk aversion agents will place great value on tax induced

taxes and international risk sharing abstract we extend a standard model of international risk sharing to include an empirically plausible distortion taxes the tax inclusive theory implies even under full risk sharing a predictable relationship between consumption growth and the consumption and capital income tax rates both within and across countries we find strong empirical evidence in favor of this relationship while idiosyncratic output fluctuations account for substantially more of cross country consumption growth variability than do taxes trends in tax differentials are found to be informative about the dynamic evolution of international risk sharing in particular adjusting for capital taxes reveals a marked improvement in risk sharing over the last three decades that is absent in baseline measures this improvement has been driven by the convergence of average tax rates on capital income across oecd countries toward the united states average capital tax rate

partial insurance and investments in children this article studies the impact of permanent and transitory shocks to income on parental investments in children we use panel data on family income and an index of investments in children from the children of the national longitudinal survey of youth we find that there is partial insurance of parental investments against permanent income shocks but the magnitude of the estimated responses is small we cannot reject the hypothesis of full insurance against temporary shocks another interpretation of our findings is that insurance possibilities are limited but the fact that skill is a non separable function of parental investments over time results in small reactions of these investments to income shocks especially at later ages

incomplete intertemporal consumption smoothing and incomplete risk sharing this paper develops a method to estimate jointly the degree of intertemporal consumption smoothing and the degree of inter regional risk sharing the empirical results for the u s states and oecd and eu countries suggest that i regardless of the assumption on the degree of intertemporal consumption smoothing the degree of risk sharing within a country is larger than across countries ii the degree of intertemporal consumption smoothing within a country is also larger than across countries and iii the difference between the degree of intertemporal consumption smoothing within u s states and across oecd and eu countries is as large as the difference between the degree of risk sharing contrary to the findings of some past studies

intranational risk sharing and its determinants abstract we develop a model of risk sharing in which agents can pool their consumption risks in both national and local markets and then smooth the remaining consumption fluctuations with credit markets estimating the model with a unique dataset on chinese cities we find that the participation rate in risk sharing is low but upon entering the market agents tend to pool risk in the national market rather than the local market the welfare gain from reaching the perfect consumption risk sharing at the national market could be as large as 4 of the perpetual deterministic consumption flow however conditional on the estimated degree of risk sharing participation the welfare gain from pooling all income risks at the national market is only 0 1 empirical analysis on the determinants of city risk sharing reveals that the degree of risk sharing depends on initial economic development and share of gdp contributed by tertiary industry

risk sharing with limited commitment and preference heterogeneity structural estimation and testing in order to analyze the role of limited commitment and preference heterogeneity in explaining the consumption allocation i propose a theoretical and empirical framework to estimate and evaluate a risk sharing model where insurance transfers have to be self enforcing and the coefficient of relative risk aversion may depend on observable household characteristics i compare this model to benchmark models with full commitment and or without preference heterogeneity using data from three indian villages i find that the limited commitment model with heterogeneous preferences outperforms the benchmark models in a statistical sense and in terms of i explaining the dynamic response of consumption to idiosyncratic income shocks ii accounting for the variation of consumption unexplained by household and time effects and iii capturing the variation of inequality across time and villages and predicting changes in inequality i also use the estimated models to predict the effects of a counterfactual tax and transfer policy on the consumption allocation the limited commitment model with preference heterogeneity predicts larger benefits to the poor than its homogeneous counterpart

consumption network effects in this paper we study the relevance and mechanics of consumption network effects we use long panel data on the entire danish population to construct a measure of consumption based on administrative tax records and define the peer groups in terms of workplace occupation education and age we then apply an iv strategy and fixed effect models to recover the effects our instruments arise naturally from the network structure and firms shocks the estimated effects are statistically significant and relevant for policies as they generate non negligible multiplier effects further the results are consistent with a keeping up model

estimating a dynamic adverse selection model labour force experience and the changing gender earnings gap 1968 1997 this paper addresses two questions what accounts for the gender gap in labour market outcomes what are the driving forces behind the changes in the gender labour market outcomes over the period 1968 1997 it formulates a dynamic general equilibrium model of labour supply occupational sorting and human capital accumulation in which gender discrimination and an earnings gap arise endogenously it uses this model to quantify the driving forces behind the decline in the gender earnings gap and the increase in female labour force participation the proportion of women working in professional occupations and hours worked it finds that labour market experience is the most important factor explaining the gender earnings gap in addition statistical discrimination accounts for a large fraction of the observed gender earnings gap and its decline it also finds that a large increase in aggregate productivity in professional occupations plays a major role in the increase in female labourforce participation number of hours worked and the proportion of females working in professional occupations although of less importance demographic changes account for a substantial part of the increase in female labour force participation and hours worked whereas home production technology shocks do not

village and larger economies the theory and measurement of the townsend thai project i have spent close to 20 years cataloging transactions between households in thai villages along with a research team just this past summer we documented a number of ways in which even relatively poor villages have money markets not dissimilar in some ways from new york financial markets with borrowing and repayment passing along links in credit chains in another project we have been looking at month by month school attendance grade level completion and graduation for children in these villages following them from birth to graduation the townsend thai project is a theory based data collection endeavor measuring and mapping village and larger economies into general equilibrium frameworks this paper reviews a number of findings implications applications and lessons learned and considers next steps

implications of endogenous group formation for efficient risk sharing the existing literature on sub game perfect risk sharing suffers from a basic inconsistency while a group of size n is able to coordinate on a risk sharing outcome it is assumed that deviating subgroups cannot i relax this assumption and characterise the optimal contract among all coalition proof history dependent contracts this alters the predictions of the standard dynamic limited commitment model i show that the consumption of constrained agents depends on both the history of shocks and its interaction with the current income of other constrained agents from this i derive a formal test for the presence of endogenous group formation under limited commitment

communication commitment and growth abstract we study the effect on the growth of an economy of alternative financing opportunities in a stochastic growth model with incentive constraints efficient accumulation mechanisms are designed and computed for economies that differ in their incentive structure we show that when borrowing is subject to information constraints there is a computable efficient transfer mechanism that does not affect capital accumulation and investment patterns even though consumption patterns and the distribution of wealth are affected in contrast enforcement constraints can severely reduce the outside financing opportunities and affect investment patters and economic growth we adapt numerical algorithms for obtaining numerical solutions of these models

full insurance in the presence of aggregate uncertainty this paper tests implications of full consumption insurance the object is to determine how much mileage can be obtained from a model with complete markets with such features as private information or liquidity constraints omitted the implication exploited is that individual consumption responds to aggregate risk but not to idiosyncratic risk the test involves regressing the change in household consumption onto the change in aggregate consumption and other right hand side variables such as the change in household income and change in employment status all variables other than the change in aggregate consumption are predicted to be insignificant in explaining the change in household consumption with observations on consumption and income for 10 695 households from the consumer expenditure survey the results are mixed the results for one specification exponential utility are mostly consistent with full consumption insurance the results for the other specification power utility are not

on the empirics of risk sharing across mena countries in this article we compute the potential welfare gains and the realized gains from risk sharing among middle east and north african mena countries including the oil rich gulf region and the resource scarce economies we find that the overall potential welfare gains across mena countries are positive for all countries under the assumption of full risk sharing the potential welfare gains among the six gulf cooperation council gcc countries are positive even though the magnitudes are smaller compared to those of the rest of the mena region we also quantify the extent of risk sharing for the mena region and show that it is significant for the mena region and its subgroups however we could not find any sign of inter temporal smoothing across the same groups decomposing the aggregate output shocks shows that the extent of risk sharing is significant when only positive output shocks exist across the resource scarce mena economies however we observe that gcc countries share output risks with each oth

identifying vulnerability to poverty a critical survey in the economic literature on poverty various methods have been proposed for measuring a phenomenon known as vulnerability however after more than a quarter century of research no consensus has been reached on how to identify such vulnerable individuals within a given population some misunderstandings have also arisen from the overlapping of other closely related concepts such as the expectation of being poor expected poverty multi period poverty and risk exposure this paper offers a detailed conceptual discussion on vulnerability to poverty and its related elements reviewing a wide range of identifying criteria provided in the literature it is found that according to the state of the art in this field of research two key elements stand out in identifying vulnerable individuals an expected well being below the poverty line and a relevant risk of falling into poverty due to downside deviation from a reference level of well being the traditional classification of vulnerability approaches has been updated into four groups i those that stress the element of exposure to risk ii those that emphasize the element of expected poverty iii those that define vulnerability through a utility gap and iv those that are supported by a mean risk dominance criterion

the efficient allocation of consumption under moral hazard and hidden access to the credit market in this paper we describe the properties of the optimal allocation of consumption in a world with moral hazard and hidden borrowing and lending we discuss how and under what conditions the efficient allocation can be distinguished from that of the permanent income self insurance model we also compare our allocation with the complete markets full information case and with the standard moral hazard model with monitorable and fully contractible asset holdings jel d82 e21 jel d82 e21 jel d82 e21 jel d82 e21

when faced with income and asset shocks do poor rural households in vietnam smooth food consumption or assets abstractvietnamese rural households are exposed to severe covariate and idiosyncratic shocks however these households are remarkably resilient and have steadily increased real income and consumption over the survey period 2006 to 2012 to explain household strategies to cope with shocks we test three theoretical models the permanent income hypothesis pih complete market hypothesis cmh and asset smoothing theory ast there is support for ast as households smooth productive assets rather than consumption and for cmh as households smooth consumption against idiosyncratic but not covariate shocks there is no support for pih

consumption and aggregate constraints evidence from u s states and canadian provinces state level consumption exhibits excess sensitivity to lagged income to the same extent as u s aggregate data but state specific idiosyncratic consumption exhibits substantially less sensitivity to lagged state specific income a result that also holds for canadian provinces we propose the following interpretation borrowing and lending in response to changes in consumer demand are easier for individual u s states than for the united states as a whole and therefore the measured deviation from the benchmark permanent income hypothesis model is smaller however lagged state specific variables help predict state specific consumption suggesting that the pih model still requires qualification

home bias and international risk sharing twin puzzles separated at birth abstract we document that international home bias in debt and equity holdings declined during the period 1993 2003 at the same time as international risk sharing increased using panel data regressions for oecd countries we demonstrate that less home bias is associated with more international risk sharing more generally we show that more financial integration is associated with more risk sharing when we measure financial integration as the ratio of foreign assets to gross domestic product our results indicate that risk sharing and international financial integration are closely related empirical phenomena

are rainfed agricultural households insured evidence from five villages in vidarbha india there are several studies on risk and insurance in village economies in the developing world however there is a lack of evidence for recent decades in spite of profound changes including structural transformation and widespread market liberalization in most regions in this paper i use primary panel data from five rainfed villages in a high risk region of india and find evidence of considerable exposure as well as vulnerability to idiosyncratic and covariate risks further there is significant wealth differentiated heterogeneity in vulnerability the findings help identify the scope of public policy in improving risk management in rainfed agriculture

parental benefits from intergenerational coresidence empirical evidence from rural pakistan this paper explains the negative correlation between the days of work reported by fathers in rural pakistani households and the incomes earned by their coresident adult sons thereby contributing to research on the benefits from intergenerational coresidence i find that the decline in fathers days of work that accompanies increases in sons incomes primarily results because such income is used to finance expenditures on household public goods such as consumer durables and ceremonies empirical tests reject most alternative explanations of the benefits of coresidence including the belief that sons contribute to fathers wealth

marriage and consumption insurance what s love got to do with it when markets are incomplete individuals may choose to marry to diversify their labor income risk love however can complicate the picture if love is fleeting or the resolution of agents income uncertainty occurs predominantly later in life then marriages with good economic matches last longer in contrast if love is persistent and the resolution of uncertainty to agents income occurs early then marriages with good economic matches are more likely to be caught short with too little love to save a marriage consequently once married the partners will be more likely to divorce evidence is provided to distinguish between these alternative scenarios

risk sharing networks and insurance against illness most risk sharing tests on developing country data are conducted at the level of the village generally the full risk sharing hypothesis is rejected this paper uses detailed data on all insurance networks within a village in tanzania networks are not clustered but largely overlapping we test whether full risk sharing occurs within these networks while village level full insurance cannot be rejected for food consumption we find evidence consistent with at least partial insurance of non food consumption via networks

understanding consumption smoothing evidence from the u s consumer expenditure data consumption models with endogenous debt constraints differ from standard incomplete markets models in their predictions about an individual household s ability to smooth consumption across time and states of the world in this paper we develop these differences both theoretically and quantitatively we then use data from the us consumer expenditure survey ce to assess along which dimensions the predictions of these models are consistent with the empirical evidence we find that both type models fail to fully account for the data and argue that a model that combines aspects of both might be more succesfull

growth and risk sharing with private information abstract we examine the impact of incomplete risk sharing on growth and welfare the source of market incompleteness in our economy is private information a household s idiosyncratic productivity shock is not observable by others risk sharing between households occurs through long term contracts with intermediaries we find that incomplete risk sharing tends to reduce the rate of growth relative to the complete risk sharing benchmark numerical examples indicate that the welfare cost and the growth effect of private information are small

risk sharing between and within families this paper uses the panel study of income dynamics to test whether risk sharing is complete between or within american families the tests accommodate a wide variety in the configuration and availability of family data the test results reject inter as well as intra family full risk sharing even assuming that leisure is endogenous or that leisure and consumption are nonseparable

evidence on the insurance effect of bankruptcy exemptions abstract defaulting on one s debts when experiencing an adverse event can help insure households against unexpected income risks but the effect of allowing default on debt levels is ambiguous not least because lenders may restrict access to credit hence the optimal punishment for bankruptcy is unclear the us states allows householders to keep a variety of assets when filing for bankruptcy the bankruptcy exemptions and these exemptions change substantially between states and over time by exploiting these differences this study shows that raising the exemptions i marginally decreases the level of unsecured debt that household s hold ii makes consumption smoother thus despite the effect on debt levels the generous provisions to debtors in arrears may be helping us households to insure themselves against income risk

on the quantitative importance of market completeness abstract this paper quantitatively compares allocations in calibrated large overlapping generations growth models that only differ in their market structures for insuring against aggregate risk the findings are that the equilibrium behavior of aggregate variables is very similar across all market structures there are only minor differences the ratio of the volatility of aggregate consumption relative to that of investment is higher in complete market economies due partly to the higher volatility of consumption of older people it was also found that the risk premia in complete markets economies is basically zero therefore we can conclude that we can for the most part abstract from the issue of whether there exist markets for aggregate risk

dynamic risksharing in the united states and europe abstract we use a panel var model to improve upon the existing methodologies to analyze interregional risksharing and consumption smoothing channels first we endogenize the output process within a more general multi equation framework capturing the dynamic feedback between output and various smoothing channels second in line with dynamic general equilibrium open economy models of risksharing we exploit impulse response functions to trace the role of each smoothing channel over time in the presence of different structural shocks temporary vs permanent and output vs smoothing channels in the application to the us and oecd countries we find different dynamic properties of different smoothing channels we compare our results with the predictions of standard risksharing and consumption theories and tackle some of the puzzles in the literature such as the international risksharing puzzle and the consumption output correlation puzzle we are also able to address such policy issues as whether fiscal stabilizers have been substitutes or complements for financial market diversification activities and whether further financial market integration is likely to provide countries with more shock absorption tools a key result is the strong substitutability between capital and credit smoothing in the us and between fiscal and credit smoothing in the oecd

risk sharing within families evidence from the health and retirement study abstract we report strong empirical support for the presence of self interest based risk sharing within extended families in the u s a standard model of self interest based risk sharing predicts that the share of current family income consumed by a child positively depends on that child s permanent income it follows that parental transfers to children that are expected to earn more over the period of risk sharing arrangements should exhibit less sensitivity to the recipient s income fluctuations we test this distinguishing prediction of self interest based risk sharing by exploiting the variation of transfer receipts among siblings observed over 17 years of longitudinal data spanned by the health and retirement study

testing for full insurance using exogenous information we strongly reject the full insurance hypothesis using testing variables that are not decision variables for the households under investigation we find that households are not insured against changes in the unemployment rate associated with the household head s occupational category using this exogenous information we also investigate the appropriateness of exogeneity assumptions on idiosyncratic variables that have been used as testing variables in the full insurance literature it is shown that several exogeneity assumptions made in the existing literature are potentially problematic

credit constraints and the measurement of time preferences incentivized experiments are often used to identify the time preferences of households in developing countries we argue theoretically and empirically that experimental measures may not identify pr

consumption real exchange rates and the structure of international asset markets abstract international real business cycle irbc models that assume complete asset markets yield strong restrictions for consumption and bilateral real exchange rate series empirical tests with data for the us japan france uk italy canada and sweden suggest that neither the trend behavior nor high frequency movements of consumption and real exchange rates are well explained by irbc models with complete markets it appears however that high frequency fluctuations of consumption and real exchange rates are consistent with unrestricted international trade in risk free bonds

networks in economic development this chapter surveys the implications of some studies in network economics research for economic development we focus on information flow and risk sharing two topics where work in theory empirics and policy analysis have been especially intensive and complementary in analysing information we distinguish models of information diffusion and aggregation highlight how different models imply very different guidance regarding the right way to seed information in discussing risk sharing we look at the key frictions that impede efficient informal insurance and some potential unintended consequences when policymakers intervene to help throughout we stress practical insights that can be used with limited measurement of the details of networks

consumption and investment in resource pooling family networks this paper examines a novel motive for resource pooling in family networks in rural economies to relax credit constraints and facilitate investment in non collateralizeable assets for which credit market imperfections are most binding we thus complement established literatures examining risk sharing motives for resource transfers within family networks as well as motives based on kinship tax obligations we do so exploiting the progresa program data in which family networks can be identified households are subject to large exogenous resource inflows and detailed responses on consumption and an array of investments can be tracked in a household panel over five years we find that for every dollar that accrues to the family network through progresa transfers food consumption expenditures increase by around 65c for both households eligible for progresa and ineligible members of the same family network hence the marginal propensity of families to invest save out of every dollar is around 35 and we document how this is channelled towards easing credit constraints poorer network members face in financing non collateralizable investments into their children s human capital we show these consumption and investment benefits of being embedded within a family network are sustained five years after households first experience resource transfers from progresa hence the interplay between resource inflows and resource pooling by family networks can place network members on sustained paths out of poverty this article is protected by copyright all rights reserved

contingent loan repayment in the philippines abstract using data from the philippines this article seeks to understand how households in the study area apparently manage to avoid falling into a debt trap in spite of frequent borrowing findings suggest that this is achieved via three institutional features first most informal debt carries no interest second for all debts repayment is postponed in case of a borrower s difficulty this is the only insurance feature of debt repayment third while debt principal is seldom forgiven or reduced interest bearing debt does not carry additional interest if debt repayment is delayed this prevents interest charges from accumulating and debt from snowballing

insuring consumption against illness one of the most sizable and least predictable shocks to economic opportunities in developing countries is major illness we investigate the extent to which families are able to insure consumption against major illness using a unique panel data set from indonesia that combines excellent measures of health status with consumption information we find that there are significant economic costs associated with major illness and that there is very imperfect insurance of consumption over illness episodes these estimates suggest that public disability insurance or subsidies for medical care may improve welfare by providing consumption insurance

risk sharing and transactions costs evidence from kenya s mobile money revolution we explore the impact of reduced transaction costs on risk sharing by estimating the effects of a mobile money innovation on consumption in our panel sample adoption of the innovation increased from 43 to 70 percent we find that while shocks reduce consumption by 7 percent for nonusers the consumption of user households is unaffected the mechanisms underlying these consumption effects are increases in remittances received and the diversity of senders we report robustness checks supporting these results and use the four fold expansion of the mobile money agent network as a source of exogenous variation in access to the innovation jel e42 g22 o16 o17 z13 in developing countries informal networks provide an important means by which individuals and households share risk though the insurance they provide is often incomplete economists have proposed a number of reasons for this incompleteness including information asymmetries which manifest in problems of moral hazard and limited commitment both of which induce positive correlations between realized income and consumption in this article we emphasize a complementary source of incompleteness transaction costs literally the costs of transferring resources between individuals we test the impact of transaction costs on risk sharing by analyzing data from a large panel household survey that we designed and administered in kenya over a three year period to capture the expansion of mobile money this financial innovation has allowed individuals to transfer purchasing power by simple short messaging service sms technology and has dramatically reduced the cost of sending money across large distances mobile money is a recent innovation in developing economies one of the first and most successful examples to date is kenya s m pesa 1 in just four years after its

market incompleteness and the equity premium puzzle evidence from state level data abstract this paper investigates the importance of market incompleteness by comparing the rates of risk aversion estimated from complete and incomplete markets environments for the incomplete markets case we use consumption data for the 50 us states we find that the rate of risk aversion under the incomplete markets setup is much lower furthermore including the second and third moments of the cross sectional distribution of consumption growth in the pricing kernel lowers the estimate of risk aversion these findings suggest that market incompleteness ought to be seen as an important component of solutions to the equity premium puzzle

international risk sharing in the short run and in the long run international risk sharing has far reaching implications both for economic policy and for basic research in economics when countries do not share consumption risk individuals experience consumption fluctuations that are undesirable and possibly unnecessary we investigate bilateral risk sharing at short vs long horizons we find substantial cross country consumption correlations at trend and business cycle frequencies correlations are particularly high within europe prior research focused on first difference correlations which are typically quite low we argue that this reflects measurement error at all horizons we find that consumption correlations are not significantly different from output correlations implying a lack of deliberate consumption risk sharing le partage international du risque a de grandes implications a la fois pour la politique economique et pour la recherche economique de base quand des pays ne partagent pas les risques de consommation les individus font l experience de fluctuations de consommation indesirables et possiblement non necessaires on examine le partage de risque bilateral a court et a long terme on decouvre des correlations entre pays tant au niveau des tendances que des frequences du cycle d affaires ces correlations sont particulierement elevees en europe des travaux anterieurs se sont concentres sur les correlations entre premieres differences qui sont typiquement assez faibles on suggere que ces resultats refletent une erreur de mesure pour tous les horizons temporels on decouvre que les correlations de consommation ne different pas significativement des correlations de production ce qui implique un manque de partage de risque delibere au niveau de la consommation

the effect of work experience on female wages and labour supply this paper develops and implements a semiparametric estimator for investigating with panel data the importance of human capital and time nonseparable preferences to females when aggregate shocks are present it provides a set of conditions for making statistical inferences about agents expectations of their correlated future choices from a short panel under the assumption that observed allocations are pareto optimal a dynamic model of female labour supply and participation is estimated in which experience on the job raises future wages and time spent off the job in the past directly affects current utility or indirectly through productivity in the nonmarket sector

supply side strategic unemployment in small business in this paper the model which will be analysed is characterized by a labour market with a profitable vacancies b unemployment c excess labour supply d limited mobility and divisibility of labour and e competition on the job the analysed setting is typical for a small business economy the analysis suggests that unemployment will be greater than equilibrium unemployment if present employees and potential entrants consider job assignments for this market under strategic perspectives

risk pooling between households and risk coping measures in developing countries evidence from rural bangladesh abstract using data from rural bangladesh i test whether income risks are pooled among villagers between neighboring households and between related households living in different villages i find evidence that risks to food consumption are pooled between neighboring households and between related households but not among villagers as for nonfood consumption i find little evidence of risk pooling except between unrelated neighboring households i also find that while households belonging to a neighborhood network do not take any special measures during an economic hardship those not belonging to any such network try to smooth consumption by selling off livestock and other assets and by getting interest free loans negative income shocks are found to have little effect on labor supply or private transfers

testing efficient risk sharing with heterogeneous risk preferences previous papers have tested e cient risk sharing under the assumption of identical risk preferences in this paper we show that if in the data households have heterogeneous risk preferences the tests proposed in the past reject e ciency even if households share risk e ciently to address this issue we propose a method that enables one to test e ciency even when households have difierent preferences for risk the method is composed of three tests the flrst one can be used to determine whether in the data under investigation households have homogeneous risk preferences the second and third test can be used to evaluate e cient risk sharing when the hypothesis of homogeneous risk preferences is rejected we use this method to test e cient risk sharing in rural india using the flrst test we strongly reject the hypothesis of identical risk preferences we then test e ciency with and without the assumption of preference homogeneity in the flrst case we reject e cient risk sharing at the village and caste level in the second case we still reject e ciency at the village level but we cannot reject this hypothesis at the caste level this flnding suggests that the relevant risk sharing unit in rural india is the caste and not the village

imperfect insurance and differing propensities to consume across households abstract this paper extends previous tests of consumption insurance by splitting the sample to examine whether the marginal propensity to consume mpc out of idiosyncratic income shocks is larger for low wealth households than it is for high wealth households using data from the psid i find 1 the mpc of low wealth households is higher than that of high wealth households there are indications that both precautionary savings behavior and liquidity constraints contribute to this difference 2 splitting the data using two different measures of wealth indicates that households perceive housing equity as illiquid 3 when low wealth households are split into two subgroups the mpc of the very low wealth group is smaller reflecting the insurance aspects of means tested safety net programs

labour market institutions and household consumption insurance within oecd countries this paper tests empirically whether the effect of idiosyncratic income shocks on aggregate consumption depends on institutional features of national labour markets the results show that in a sample of 15 oecd countries institutional heterogeneity is a significant determinant of the response of household consumption to country specific income shocks this is consistent with the idea that institutionally provided social insurance may help increase income stability when people differ in their ability to access financial markets and smooth consumption fluctuations

incentives and aggregate shocks this paper presents an incentive based theory of the dynamics of the distribution of consumption in the presence of aggregate shocks the paper builds on the models concerning the distribution of income or consumption and incentive problems of green 1987 thomas and worrall 1991 phelan and townsend 1991 and atkeson and lucas 1992 by incorporating aggregate production shocks the model allows an examination of the interactions between individual and aggregate consumption series given incomplete insurance further the methodology outlined allows the incorporation of incentive considerations to macroeconomic environments similar to rogerson 1988 and hansen 1985

welfare gains from international risksharing abstract this paper uses consumption data to compute yet unexploited welfare gains that can be achieved through risksharing among twenty oecd countries there is both aggregate national consumption risk and nondiversifiable individual specific risk countries engage in an optimal risksharing arrangement to pool risk associated with the aggregate consumption endowment streams welfare gains are associated with reduced consumption variability and with the international pricing of the consumption streams of individual countries the paper considers the standard vnm time additive preferences as well as nonexpected utility and habit formation preferences large unexploited gains are found under all sets of preferences leading to an international risksharing puzzle

risk and insurance in village india comment the protection of poor households in high risk agrarian economies from shocks to their incomes has often been seen as a compelling motive for various forms of policy intervention including transfers of cash or food credit subsidies and public employment schemes for a survey see lipton and ravallion 1995 the desirability of such safety net policies clearly depends on how well pre existing risk sharing arrangements work while it is commonly thought that without effective policy intervention rural households are vulnerable to village wide shocks such as adverse prices or poor rains it is less clear to what extent risk sharing institutions within the village mitigate the effects of idiosyncratic income risk stemming for instance from ill health or localized crop damage 2 several recent papers have used household level data to implement tests of risk sharing that might inform such concerns 3 these tests are based on the proposition that with perfect risk sharing consumption at the household level should be insured against idiosyncratic risks and thus depend solely on the realization of the aggregate risk wilson 1968 diamond 1967 townsend 1994 tests this implication of perfect intra village risk sharing using longitudinal household data on consumptions and incomes for three villages in india he reports that the full insurance hypothesis provides a surprisingly good benchmark in that household consumptions co move and do not appear to be much influenced by contemporaneous own income our aim here is to examine the robustness of this potentially important finding we have two main concerns the first is that the specification townsend adopts potentially biases his test towards the null hypothesis of full insurance because it yields inconsistent estimates of the key test parameter under a plausible alternative we therefore estimate a different specification that generates consistent estimates under both the null and the alternative our second concern is that a particular form of measurement error in the consumption data townsend uses may have further biased his results toward the null hypothesis of full insurance to address this concern we use an instrumental variables procedure when we implement the test of consumption insurance with townsend s consumption data we also re estimate the test equations with a measure of consumption derived from the same underlying primary data by an alternate method finally townsend reports 1discussions with robert townsend stimulated our interest in this investigation the staff of the

consumption patterns as a measure of capital mobility evidence from some apec countries consumption patterns are used to measure capital mobility within the apec region both on a bilateral and multilateral basis two models are estimated by iv sur and ols using quarterly data for four countries the us japan canada and australia the results show that the hypothesis of perfect capital mobility is rejected and some results even indicate autarky it is argued however that the hypothesis of perfect capital mobility is unreasonable and that the consumption criterion is inappropriate because it assumes real interest equalization

china s energy security perception and reality abstract china now the world s second largest economy is worried about energy security which underpins the core objectives of beijing and the political legitimacy of the communist party of china the purpose of this study is to explore certain popular myths about china s energy security the study consists of six parts after the introduction it formulates the obscure concept of energy security and attempts to contextualize it with chinese characteristics then it explicitly points out that the largest driver of oil demand by china as the world s factory is transport instead of industry next it explores the effectiveness of transnational pipelines as a measure of energy security and explains why they are less effective than many observers have previously assumed furthermore it investigates the global expansion of chinese national oil companies and questions their actual contribution to energy security a few concluding remarks then follow

a simple test of consumption insurance are consumers effectively insured against idiosyncratic shocks to income or wealth either by formal institutions such as charities private insurance and government programs or by informal mechanisms such as gifts and loans from relatives friends and neighbors under full insurance consumption growth should be cross sectionally independent of idiosyncratic variables that are exogenous to consumers this proposition is tested by cross sectional regressions of consumption growth on a variety of exogenous variables full insurance is rejected for long illness and involuntary job loss but not for spells of unemployment loss of work due to strike and an involuntary move

debt crises and risk sharing the role of markets versus sovereigns debt crises and risk sharing role of markets versus sovereigns using a variance decomposition of shocks to gross domestic product gdp we quantify the role of international factor income international transfers and saving in achieving risk sharing during the recent european crisis we focus on the subperiods 1990 2007 2008 2009 and 2010 and consider separately the european countries hit by the sovereign debt crisis in 2010 we decompose risk sharing from saving into contributions from government and private saving and show that fiscal austerity programs played an important role in hindering risk sharing during the sovereign debt crisis

from earnings inequality to consumption inequality this paper studies the paths from inequality in earnings to inequality in household consumption we show that careful study of the evolution of the variances and covariances of earnings and consumption within cohorts across time can identify permanent and transitory shocks we present an application to the evolution of inequality in the united kingdom we extend previous results to recognise separate earnings of partners in couples

quantitative asset pricing implications of endogenous solvency constraints we study the asset pricing implications of an economy where solvency constraints are endogenously determined to deter agents from defaulting while allowing as much risk sharing as possible we solve analytically for efficient allocations and for the corresponding asset prices portfolio holdings and solvency constraints for a simple example then we calibrate a more general model to u s aggregate as well as idiosyncratic income processes we find equity premia risk premia for long term bonds and sharpe ratios of magnitudes similar to the u s data for low risk aversion and a low time discount factor article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

marriage divorce and interstate risk sharing in this paper we study the importance of marriage for interstate risk sharing in the us we find that us federal states in which married couples account for a higher share of the population are less exposed to state specific output shocks thus in addition to improving the allocation of risk at the individual level marriage also has implications for risk sharing at the more aggregated state level quantitatively the impact of marriage on interstate risk sharing varies over divorce regimes

mitigating the consequences of a health condition the role of intra and interhousehold assistance the behavior of noncoresident family members motivates much of the literature on consumption smoothing risk sharing and informal networks yet little is known empirically on the topic due to a lack of data simultaneously observing multiple households in an extended family this study utilizes genealogically linked longitudinal data to examine how extended family networks insure against financial risks from severely limiting health conditions we find that nonhealth consumption of unmarried households declines in response to worsening health whereas married households smooth expenditures in a way that is consistent with full insurance families mitigate losses by reallocating home production drawing down home equity holding formal health insurance collecting social security and receiving transfers from noncoresident relatives we illustrate that the costs of health shocks are transmitted throughout family networks and that noncoresident children draw down their assets and consumption when responding to a parent s health decline

the introduction of formal insurance and its effect on redistribution abstract transfers motivated by altruism guilt and norms of giving play an important role in supporting individuals who suffer losses due to risk we present empirical evidence from an artefactual field experiment in ethiopia in which we introduce formal insurance in a setting where donors make redistributive transfers to recipients who experience losses we find that donors tend to reduce their transfers to recipients who are offered insurance whether or not they take it up when insurance is rejected by a recipient transfer reductions are larger for donors who firmly expect that the recipient would take up insurance the results are consistent with a framework in which the introduction of insurance erodes norms of giving by revealing differences in the extent to which individuals value precautionary behavior with respect to risk taking welfare calculations show that when formal insurance is introduced the welfare of those who fail to take it up may be reduced

poverty and the welfare costs of risk associated with globalization summary globalization implies change and uncertainty over future change may affect household welfare we use data on lorenz curves over the last 50 years for a sample of 53 mostly developing countries treating each country quintile year as an observation we first account for variation in consumption expenditures finding that global shocks are of less importance than country level shocks in explaining variation in country quintile consumption growth while poorer households experience more rapid consumption growth than do wealthier households they also bear much more risk however we find no evidence that this greater risk is related to globalization

income shocks consumption wealth and human capital evidence from russia abstract using the russia longitudinal monitoring survey this article investigates how russian households consumption responds to income shocks and in particular how household wealth and human capital affect the households ability to smooth consumption an instrumental variable estimation method with household fixed effects is implemented after correcting for potential problems of sample attrition using the inverse probability weighting method the article finds that household consumption in russia is only partially protected from idiosyncratic shocks the analysis also provides evidence that wealthier households can better smooth their consumption furthermore changes in income have less impact on consumption when households have members with higher education levels wealth effects are more pronounced in rural areas while education effects are stronger for urban households

relative wage movements and the distribution of consumption we analyze how relative wage movements among birth cohorts and education groups affected the distribution of household consumption and economic welfare our empirical work draws on the best available cross sectional data sets to construct synthetic panel data on u s consumption labor supply and wages during the 1980s we find that low frequency movements in the cohort education structure of pretax hourly wages among men drove large changes in the distribution of household consumption the results constitute a spectacular failure of between group consumption insurance a failure not explained by existing theories of informationally constrained optimal consumption behavior a welfare analysis indicates that the cost of between group consumption variability is larger than the cost of aggregate consumption variability by two orders of magnitude

motives for household private transfers in burkina faso abstract resource transfers among households have received considerable interest among economists in recent years two of the main reasons for the surge of interest in household transfers are the information on human nature conveyed by transfer behavior and the implication on income redistribution policy that private transfer might have empirical studies however provide mixed results on transfer behavior this is because previous inquiries were confronted with several estimation issues and have focused on data from developed countries where private transfers are already small this paper contributes to the literature on transfer behavior by using a multifaceted econometric approach to examine the motives of household transfers in burkina a low income country with a well documented tradition of gift exchanges the findings suggest that risk sharing is not central to transfers altruistic transfers are apparent for the middle income class but not at low income level the evidence implies that crowding out may be minimal at low income level suggesting that public transfers targeting poor households may be effective

redistribution and risk sharing in italy learning from the past abstractredistribution and risk sharing in italy learning from the past regional studies this paper investigates the role of public policies in italy by assessing both the redistribution and the risk sharing functions of interregional net fiscal flows in the long run its comparative approach allows one to contrast results obtained for two periods characterized by diverse regional policy and dynamics of regional convergence although based on a specific example the evidence supports more general conclusions when assessing the regional redistributive and risk sharing power of national fiscal policies many different factors related to the existing policy regime should be accounted for particularly the distribution of government spending between current expenditure and public investment

financial integration and international risk sharing abstract conventional wisdom suggests that financial liberalization can help countries insure against idiosyncratic risk there is little evidence however that countries have increased risk sharing despite widespread financial liberalization we show that the key to understanding this puzzling observation is that conventional wisdom assumes frictionless international financial markets while actual markets are far from frictionless financial contracts are incomplete and contract enforceability is limited when countries remove official capital controls default risk is still present as an implicit barrier to capital flows if default risk were eliminated capital flows would be six times greater and international risk sharing would increase substantially

a microeconometric comparison of household behavior between countries this article reviews the methodological issues associated with estimating and testing competitive markets with panel data and applies it to an important new arena international economics we investigate differences in housing consumption and male labor supply across households in germany and the united states with data from the german socio economic panel and the panel study of income dynamics observations are treated as equilibrium outcomes generated by a set of competitive markets that accommodate varying degrees of integration after controlling for differences in the sample populations and aggregate shocks we find that the estimated structural parameters are surprisingly similar across these two countries

consumption risk sharing in italy this paper analyses the issue of consumption risk sharing in the 20 italian regions during the period 1983 94 the tests proposed allow for regional specific departures from the hypothesis of complete risk sharing and for the existence of non separabilities among groups of commodities empirical evidence suggests the rejection of the hypothesis of complete consumption risk sharing

international risk sharing and commodity prices cole and obstfeld 1991 exposited a classic result where equilibrium movements in the terms of trade could make ex ante risk sharing arrangements unnecessary a unity elasticity of substitution across goods and production specialization this paper extends their model to n countries and m commodities n m here the terms of trade provides insurance against commodity specific shocks not country specific shocks using commodity level production data at the national level and world commodity prices we document significant terms of trade variability and positive responses of nation specific production to terms of trade improvements the endogenous terms of trade insurance mechanism highlighted in co is virtually non existent cole et obstfeld 1991 ont developpe un resultat classique montrant que les mouvements d equilibre dans les termes d echange pouvaient faire l economie d arrangements ex ante pour le partage du risque une elasticite de substitution unitaire entre biens et specialisations dans la production ce texte developpe leur modele pour n pays et m biens n m les termes d echange fournissent l assurance contre les chocs specifiques a certains biens mais non contre les chocs en provenance de certains pays utilisant des donnees de production au niveau des biens au plan national et des prix des biens au niveau mondial on observe une variabilite significative des termes d echange et des reponses positives de la production specifiquement nationale aux ameliorations dans les termes d echange le mecanisme endogene d assurance via les termes d echange mis en lumiere par co est virtuellement non existant

how responsive are private transfers to income evidence from a laissez faire economy abstract in recent years there has been burgeoning interest in how private transfers respond to household income or transfer derivatives much of it is fueled by the specter of crowding out the more responsive are private transfers the more likely they could be supplanted by expansions in public transfers weakening or destroying the latter s distributive impact yet there is also an emerging consensus that actual transfer derivatives are trivial at least for the united states suggesting that crowding out might loom larger in the minds of some economists than in the data but perhaps crowding out is a fait accompli in the united states accordingly we focus on the philippines which has a much smaller public sector we also pursue a novel theoretical angle which generates a sharp non linear relationship between private transfer receipts and income in the form of a spline our empirical work applies recently developed estimation techniques that treat the spline s threshold as an unknown parameter and they uncover transfer derivatives much larger than conventional methods reveal notably private transfers patterns are consistent with altruistic preferences effective risk sharing or both in accord with theoretical predictions however strong transfer derivatives prevail only among low income households our findings suggest that attempts to aid the poor could be thwarted by private responses which leak benefits to richer households in the form of lighter burdens of support for less fortunate kin so the problems that operative private transfers create for public redistribution policy first pointed out by becker and barro over 25 years ago do indeed matter empirically

intertemporal choice and consumption mobility the theory of intertemporal consumption choice makes sharp predictions about the evolution of the entire distribution of household consumption not just about its conditional mean in the paper we study the empirical transition matrix of consumption using a panel drawn from the bank of italy survey of household income and wealth we estimate the parameters that minimize the distance between the empirical and the theoretical transition matrix of the consumption distribution the transition matrix generated by our estimates matches remarkably well the empirical matrix both in the aggregate and in samples stratified by education our estimates strongly reject the consumption insurance model and suggest that households smooth income shocks to a lesser extent than implied by the permanent income hypothesis jel d52 d91 i30

decreasing relative risk aversion and tests of risk sharing the relative risk aversion rra coefficient of a household whose consumption is close to the subsistence level may be very high for example if consumption is exactly at the subsistence level the household may not be willing to bear any risk if this is the case then the rra coefficient must be a decreasing function of wealth for poor households therefore we should allow the possibility of decreasing rra drra in testing the full risk sharing hypothesis however existing tests in the empirical literature are derived using preferences that exhibit either increasing or constant rra even when they are applied to data containing low income households we therefore use a hyperbolic absolute risk aversion hara utility which implies increasing constant and decreasing rra as special cases to test full risk sharing hypothesis using the international food policy research institute ifpri and the international crops research institute of the semi arid tropics icrisat household level data sets we find evidence in support of the drra hypothesis along with evidence favoring full risk sharing hypothesis at the village level and evidence against the hypothesis at the inter village level when rra is restricted to be constant we replicate the previous results in the literature reject the full risk sharing hypothesis at both levels our tests however reject this restriction and favor drra in almost all cases these results suggest that it is important to allow for drra in testing the full risk sharing hypothesis when data containing low income households are investigated this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this this abstract was borrowed from another version of this item

consumption risk sharing in social networks we develop a model of informal risk sharing in social networks where relationships between individuals can be used as social collateral to enforce insurance payments we characterize incentive compatible risk sharing arrangements and obtain two results 1 the degree of informal insurance is governed by the expansiveness of the network measured by the number of connections that groups of agents have with the rest of the community relative to group size twodimensional networks where people have connections in multiple directions are su ciently expansive to allow very good risk sharing we show that social networks in peruvian villages satisfy this dimensionality property thus our model can explain townsend s 1994 puzzling observation that village communities often exhibit close to full insurance 2 in second best arrangements agents organize in endogenous risk sharing islands in the network where shocks are shared fully within but imperfectly across islands as a result network based risk sharing is local socially closer agents insure each other more

long term wage fluctuations with industry specific human capital exploiting long term interindustry demand shifts this article provides evidence that 1 industry level wages do not respond to industry demand conditions 2 at the industry level the employment of young workers responds more to demand shifts than does the employment of experienced workers and 3 the postdisplacement wages of displaced workers are strongly affected by demand in their predisplacement industries these findings are consistent with a model in which worker s investments in industry specific skills pose a barrier to interindustry labor mobility and wages do not respond to spot labor market conditions

risk sharing and industrial specialization regional and international evidence the authors provide empirical evidence that risk sharing enhances specialization in production to the best of their knowledge this well established and important theoretical proposition has not been tested before the empirical procedure is summarized as follows first the authors construct a measure of specialization in production and calculate an index of specialization for each of the european community ec and non ec oecd countries u s states canadian provinces japanese prefectures latin american countries and regions of italy spain and the united kingdom then they estimate the degree of capital market integration a measure of risk sharing within each of these groups of regions the ec countries the non ec oecd countries the united states canada japan italy spain and the united kingdom and rely on another author s estimate for latin america finally they perform a regression of the specialization index on the degree of risk sharing controlling for relevant economic variables they find a positive and significant relation between the degree of specialization of individual members of a group of countries provinces states or prefectures and the amount of risk that is shared within the group the authors perform regressions using variables such as shareholder rights and the size of the financial sector relative to gdp as instruments for the amount of inter regional risk sharing these regressions confirm that risk sharing facilitated by a favorable legal environment and a developed financial system is a direct causal determinant of industrial specialization this abstract was borrowed from another version of this item

the impact of international portfolio composition on consumption risk sharing abstract recent empirical work has shown that ongoing international financial integration facilitates cross country consumption risk sharing these studies typically find that countries with high equity home bias exhibit relatively low international consumption risk sharing we extend this line of research and demonstrate that it is not only a country s equity home bias that prevents consumption risk sharing in addition the composition of a country s foreign asset portfolio plays an important role using panel data regression for a group of oecd countries over the period 1980 2007 we show that foreign investment bias has additional explanatory power for consumption risk sharing