recursive equilibria in dynamic economies with stochastic production in this paper we prove the existence of recursive equilibria in stochastic production economies with infinitely lived agents and incomplete financial markets we consider a general dynamic model with several commodities which encompasses heterogeneous agent versions of both the lucas asset pricing model and the stochastic neo classical growth model as special cases our main assumption is that there are atomless shocks to fundamentals that have a purely transitory component and a component that does not depend on last period s shocks directly

prices and investment with collateral and default abstract this paper uses the framework of an olg economy with three period lived agents in which a durable good serves as collateral for loans to study the effect of an unanticipated income shock when the economy is in a steady state equilibrium we focus on the consequence of default on loans when the value of the collateral falls below the value of the debt it secures we analyze the impulse response functions of the price and production of the durable good and show that there is an asymmetry between the response of the price and investment of the durable good to a positive and a negative income shock arising from default on the collateralized loans we show that this asymmetry can be seen in the data on housing prices and construction and is attributable to the default on mortgages in periods of decreasing prices which acts as a turbo mechanism magnifying the decline in investment

ingredients of famine analysis availability and entitlements famines often take place in situations of moderate to good food availability without any significant decline of food supply per head the paper presents an alternative approach to famines which does not concentrate on availability but on people s ability to command food through legal means available in the society including the use of production possibilities trade opportunities entitlements vis a vis the state etc the approach is explained focusing on exchange entitlement mappings fluctuations in which can lead to big shifts in the intergroup distribution of food command the approach is then applied to the bengal famine of 1943 the ethiopian famine in wollo in 1973 and the bangladesh famine in 1974 and some general conclusions are drawn about the nature and classes of famines

rural nonfarm employment and incomes in latin america overview and policy implications abstract rural nonfarm employment rnfe and incomes rnfi are crucial to latin american rural households the 11 rural household income studies in this volume reviewed in this paper use 1990s data and show that rnfi averages 40 of rural incomes rnfi and rnfe have grown quickly over the past three decades the review of evidence provided some surprising departures from traditional images of nonfarm activities of latin american rural households in terms of shares of rural incomes 1 nonfarm wage incomes exceed self employment incomes 2 rnfi far exceeds farm wage incomes 3 local rnfi far exceeds migration incomes 4 service sector rnfi far exceeds manufactures rnfi these findings suggest the need for more development program attention to wage employment in the service sector versus the traditional focus on small enterprise manufactures moreover poor households and zones tend to have higher shares in their incomes but lower absolute levels of rnfi as compared to richer households and zones the rnfe of the poor tend to be the low paid nonfarm equivalent of semi subsistence farming raising the capacity of the poor to participate in the better paid types of rnfe is crucial via employment skills training education infrastructure credit finally rnfe has grown fastest and been most poverty alleviating where there are dynamic growth motors in particular in the agricultural sector but also in tourism links to urban areas mining and forestry this means that developing rnf jobs cannot be done at the expense of programs promoting agricultural development

international financial integration and crisis contagion international financial integration helps to diversify risk but also may spread crises across countries we provide a quantitative analysis of this trade off in a two country general equilibrium model with collateral constrained borrowing using a global solution method borrowing constraints bind occasionally depending upon the state of the economy and levels of inherited debt we examine different degrees of international financial integration moving from financial autarky to bond and equity market integration financial integration leads to a significant increase in global leverage substantially escalates the probability of crises for any one country and dramatically increases the degree of contagion across countries outside of crises the impact of financial integration on macroeconomic aggregates is relatively small but the impact of a crisis with integrated international financial markets is much less severe than that under financial market autarky thus a trade off emerges between the probability of crises and the severity of crises using a large cross country database of financial crises in developing and developed economies over a forty year period we find evidence in support of the model

collateral avoids ponzi schemes in incomplete markets without introducing either debt constraints or transversality conditions to avoid the possibility of ponzi schemes we show the existence of equilibrium in an infinite horizon incomplete markets economy with a collateral structure

time varying international diversification and the forward premium abstract this paper reproduces the slope of the uncovered interest rate parity uip regression for ten country pairs within one standard deviation under rational expectations we propose an infinite horizon dynamic stochastic general equilibrium model with incomplete markets heterogeneous investors experience varying risk aversion as a result of habit formation the underlying mechanism of the model relies on varying international diversification in the investors portfolio choice decision in response to their changing habit levels investors hedging desire varies over time this leads to adjustments in interest rates the habit induced investment decisions are negatively correlated with movements in the exchange rate this results in a negative correlation between interest rates and expected exchange rates as implied by a negative uip slope depending on the magnitude of habits the model is capable of reproducing positive as well as negative uip slopes as seen empirically in the data

approximate versus exact equilibria in dynamic economies this paper develops theoretical foundations for an error analysis of approximate equilibria in dynamic stochastic general equilibrium models with heterogeneous agents and incomplete financial markets while there are several algorithms that compute prices and allocations for which agents first order conditions are approximately satisfied approximate equilibria there are few results on h interpret the errors in these candidate solutions and how to relate the computed allocations and prices to exact equilibrium allocations and prices we give a simple example to illustrate that approximate equilibria might be very far from exact equilibria we then interpret approximate equilibria as equilibria for close by economies that is for economies with close by individual endowments and preferences

verifying competitive equilibria in dynamic economies in this paper i examine e equilibria of stationary dynamic economies with heterogeneous agents and possibly incomplete financial markets i give a simple example to show that even for arbitrarily small e 0 allocation and prices can be far away from exact equilibrium allocations and prices that is errors in market clearing or individuals optimality conditions do not provide enough information to assess the quality of an approximation i derive a sufficient condition for an e equilibrium to be close to an exact equilibrium if the economic fundamentals are semi algebraic one can verify computationally whether this condition holds the condition can be interpreted economically as a robustness requirement on the set of e equilibria which form a neighbourhood of the computed approximation i illustrate the main result and the computational method using an infinite horizon economy with overlapping generations and incomplete financial markets copyright 2011 oxford university press

securitized markets international capital flows and global welfare we study the effect of collateralized lending and securitization on the global supply of securitized assets welfare and international net and gross capital flows in a two country general equilibrium model with idiosyncratic investment risk the financial sectors in the two countries home and foreign differ by the collateral requirement for investment loans with home requiring lower margins in autarky home endogenously supplies more assets and enables more risk sharing upon financial integration capital flows from foreign to home leading to lower interest rates and an increase in the global supply of assets foreign enjoys substantial welfare gains through better risk sharing and portfolio reallocation while the welfare experience for home is ambiguous gross capital flows arise when agents face aggregate shocks to the expected payoff to investment projects but can collapse when shocks concern the variance of returns

redundancy in an expanding labour market a case study of displaced workers from two manufacturing plants in southampton previous studies of redundancy have been derived from a restricted geographical base they have been predominantly concerned with workers made redundant by manufacturing firms in older industrial regions and have largely ignored redundancies in more buoyant labour market areas this paper examines the post redundancy experience of workers made redundant by two large manufacturing firms in southampton in the mid 1980s comparison with previous studies of redundancy in less prosperous labour markets in northern regions of the uk highlights contrasts in the proportions of workers finding alternative employment and in rates of pay working conditions and levels of job satisfaction the study also highlights the importance of gender in post redundancy experience another factor that has been neglected in previous studies

financial intermediation house prices and the welfare effects of the u s great recession abstract this paper quantifies the welfare costs of the great recession in the united states and their distribution between borrowing and saving households we use a calibrated dynamic general equilibrium model with shocks to aggregate income and to the financial intermediation sector the model matches the boom bust cycle in house prices the dynamics of household leverage and the increase in inequality of wealth observed in the u s after 2007 we find large welfare costs for financially constrained households the borrowers savers instead benefited from a redistribution of housing wealth due to the de leveraging of borrowers caused by the plunge in house prices this redistribution mechanism was exacerbated by the financial intermediation shock we also show that the welfare costs for borrowers would have been lower if aggregate leverage had remained at pre 2001 levels

money and market incompleteness in overlapping generations models abstract this paper investigates the extent to which the character of equilibria in stochastic overlapping generations models stems from the model s generic market incompleteness in addition it addreses the question of whether money serves to complete markets in these models we show that money does not complete markets in the sense of expanding the set of state contingent commodities that an individual may trade the introduction of money effects state contingent transfers of wealth between individuals this is a generalization of a result obtained by marshall sonstelie and gilles 1987 numerical simulation of the model suggests that the risk sharing induced in the monetary economy leads to substantial increases in welfare levels relative to the nonmonetary economy

evaluating international financial integration in a center periphery economy abstract does opening up capital markets facilitate risk diversification across borders are all countries gradually better off in the process of international financial integration this paper explores welfare implications for various countries in a center periphery framework with endogenous portfolio choice financial integration is divided into four stages financial autarky two country integration center periphery integration and global integration two effects from financial integration emerge diversification effects and financial terms of trade effects results show that financial integration between the center and a new periphery in center periphery integration generates welfare losses for the peripheral country already integrated and welfare gains for the central country allowing for financial integration between peripheries in global integration leads the welfare in the center to deteriorate from two country integration directly to global integration the large country gains while the small one loses

regulating collateral requirements when markets are incomplete in this paper we examine the eects of default and collateral on risk sharing we assume that there is a large set of assets which all promise a risk less payo but which distinguish themselves by their collateral requirements in equilibrium agents default the assets have dierent payos and there are as many linearly independent assets available for trade as there are states of the world we derive necessary and sucient conditions for equilibria to be pareto ecient in the presence of uncertainty we explore some examples for which the collateral equilibrium allocation is identical to the arrow debreu allocation either when agents have a high preference for the durable good or when the endowment distribution of the durable good is relatively homogeneous we examine a series of examples to understand which collateral levels prevail in equilibrium and under which conditions there is scope for regulating margin requirements that is restricting the sets of tradable assets through government intervention in these examples equilibrium is always sub optimal but regulation never leads to a pareto improvement while the competitive equilibria are constrained ecient there do exist regulations which make large

a two period model with portfolio choice understanding results from different solution methods using a stylized two period model we compare portfolio solutions from two local solution approaches the approach of judd and guu 2001 and the approach of devereux and sutherland 2010 2011 with the true nonlinear portfolio solution

the method of endogenous gridpoints with occasionally binding constraints among endogenous variables we show how the method of endogenous gridpoints can be extended to solve models with occasionally binding constraints among endogenous variables very efficiently we present the method for a consumer problem with occasionally binding collateral constraints and non separable utility in durable and non durable consumption this problem allows for a joint analysis of durable and non durable consumption in models with uninsurable income risk which is important to understand patterns of consumption saving and collateralized debt we illustrate the algorithm and its efficiency by calibrating the model to us data

the scramble in africa reorienting rural livelihoods abstract structural adjustment and market liberalization policies of the past 15 years have accelerated deagrarianization in sub saharan africa peasant producers have veered away from production of traditional export crops and commercial staple foods in rural areas remote from roads and urban markets nonagricultural income diversification has been substituted in the search for much needed cash earnings citing recent village survey evidence this paper argues that the economic restructuring of african smallholders work lives has been accompanied by deep rooted social change divisions of labor and decision making power within peasant households have altered and wealth differentiation between households has deepened depeasantization of the countryside is currently taking place as rural household members of both genders scramble for viable livelihoods

institutional change climate risk and rural vulnerability cases from central mexico summary a multiscalar multistressor assessment of rural vulnerability is presented illustrating how globalization market liberalization and climatic risk simultaneously structure the livelihood strategies of mexican smallholders ethnographic data collected in three communities are used to argue that farmers capacities to manage climatic risk are circumscribed by the ways in which they are able to negotiate changes in agricultural policy four livelihood strategies are explored in detail to show that market integration does not necessarily improve risk management capacity and that subsistence maize production while highly sensitive to hazards may actually serve to enhance livelihood stability the dominance of economic uncertainty over environmental risk in households decision making implies a continued role for government intervention to help households adapt to climatic stress

wealth dynamics in a bond economy with heterogeneous beliefs two types of agents have diverse beliefs about the law of motion for an exogenous endowment one knows the true process and the other learns about it via bayes theorem financial market structure affects the dynamics of the wealth distribution when markets are complete the learning agent loses wealth as in blume and easley 2006 the absence of markets for some arrow securities alters the direction in which wealth is transferred when the only traded asset is a risk free bond the learning agent accumulates wealth both agents survive and the more knowledgeable agent is driven to his debt limit

collateral requirements and asset prices many assets derive their value not only from future cash flows but also from their ability to serve as collateral in this article we investigate this collateral premium and its impact on asset returns in an infinite horizon general equilibrium model with heterogeneous agents we document that borrowing against collateral substantially increases the return volatility of long lived assets moreover otherwise identical assets with different degrees of collateralizability exhibit substantially different return dynamics because their prices contain a sizable collateral premium that varies over time this premium can be positive even for assets that never pay dividends

large market games with demand uncertainty abstract we consider a market game with a continuum of consumers where the measure of each type is stochastic nature selects the set of active consumers who make bids and offers on l 1 spot market trading posts existence of type symmetric nash equilibrium is proven when facing price uncertainty best responses are unique and a nash equilibrium to the sell all game is typically not a nash equilibrium to the original game under plausible circumstances consumers strictly prefer to be on one side of the market

international portfolios a comparison of solution methods we compare the performance of the perturbation based local portfolio solution method of devereux sutherland 2010a 2011 with a global solution method as a test suite we use model specifications that broadly capture features of international financial trade between advanced economies and between advanced and emerging economies we consider both symmetric country setups and asymmetric setups that capture important empirical facts such as differences in macroeconomic volatility differences in portfolio composition and high equity premia we find that the local method performs well at business cycle frequencies both in the symmetric and asymmetric settings while significant differences arise at long horizons in asymmetric settings

capitals and capabilities a framework for analyzing peasant viability rural livelihoods and poverty abstract on the basis of themes emerging in current debates on rural development in latin america this paper develops an analytical framework for analyzing rural livelihoods in terms of their sustainability and their implications for rural poverty the framework argues that our analyses of rural livelihoods need to understand them in terms of a people s access to five types of capital asset b the ways in which they combine and transform those assets in the building of livelihoods that as far as possible meet their material and their experiential needs c the ways in which people are able to expand their asset bases through engaging with other actors through relationships governed by the logics of the state market and civil society and d the ways in which they are able to deploy and enhance their capabilities both to make living more meaningful and to change the dominant rules and relationships governing the ways in which resources are controlled distributed and transformed in society particular attention is paid to the importance of social capital as an asset through which people are able to widen their access to resources and other actors

international capital flows portfolio composition and the stability of external imbalances abstract this paper develops a simple and tractable model of net capital flows in which time varying gross country portfolios are an essential element in current account imbalances the main constituents of country portfolios in the model are general derivatives which could be interpreted as nominal bond assets and liabilities in particular under very weak conditions the world wealth distribution is stationary stationarity is generated by movements in derivative i e bond risk premia such that the return on a debtor country s gross liabilities is less than the return on its gross assets this is well known feature of the us international investment position we also provide suggestive evidence that a similar property holds more widely for a sample of advanced and emerging market countries

endogenous leverage and asset pricing in double auctions abstract we propose a double auction mechanism for the exchange of leveraged assets and bonds in an agent based model in this framework we validate recent results in general equilibrium theory about endogenous leverage and its consequences for asset pricing we find that the institutional details of exchange are critical for a good match between the theoretical equilibrium state and the final state of the double auction specifically the outcome of the double auction is sensitive to the details of how markets for debt and collateral are coordinated and how collateral is cleared when trade is restricted to neighbours in a network final prices and allocations are significantly different from unrestricted equilibrium

endogenous market incompleteness without market frictions dynamic suboptimality of competitive equilibrium in multiperiod overlapping generations economies abstract in this paper we show that within the set of stochastic three period lived olg economies with productive assets such as land markets are necessarily sequentially incomplete and agents in the model do not share risk optimally we start by characterizing perfect risk sharing and find that it requires state dependent consumption claims which depend only on the exogenous shock realizations we show then that the recursive competitive equilibrium of any overlapping generations economy with weakly more than three generations is not strongly stationary this then allows us to show directly that there are short run pareto improvements possible in terms of risk sharing and hence that the recursive competitive equilibrium is not pareto optimal we then show that a financial reform which eliminates the equity asset and replaces it with zero net supply insurance contracts arrow securities will implement to pareto optimal stochastic steady state known to exist in the model finally we also show via numerical simulations that a system of government taxes and transfers can lead to a pareto improvement over the competitive equilibrium in the model

dynamic competitive economies with complete markets and collateral constraints in this article we examine the competitive equilibria of a dynamic stochastic economy with complete markets and collateral constraints we show that provided the sets of asset pay offs and of collateral levels are sufficiently rich the equilibrium allocations with sequential trades and collateral constraints are equivalent to those obtained in arrow debreu markets subject to a series of limited pledgeability constraints we provide both necessary and sufficient conditions for equilibria to be pareto efficient and show that when collateral is scarce equilibria are not only pareto inefficient but also often constrained inefficient in the sense that imposing tighter borrowing restrictions can make everybody in the economy better off we derive sufficient conditions for the existence of markov equilibria and for the case of two agents for the existence of equilibria that have finite support these equilibria can be computed with arbitrary accuracy and the model is very tractable

a case for incomplete markets we propose a new welfare criterion that allows us to rank alternative financial market structures in the presence of belief heterogeneity we analyze economies with complete and incomplete financial markets and or restricted trading possibilities in the form of borrowing limits or transaction costs we describe circumstances under which various restrictions on financial markets are desirable according to our welfare criterion

job loss and the regional incidence of redundancies in the current recession industrial change is a two sided process it both creates new plants production methods and jobs and displaces others at present in operation but the two sides of this process rarely coincide in time or space and in britain over the past fifteen years or so the develop ment path of the economy has been increasingly dominated by displacement effects whether measured in terms of output exports investment or employment there has been a cumulative weakening of the contribution of manufacturing to the national economy an unprecedented de industrialisation although opinions differ over the precise causes of this persistent industrial decline it is clear that the british economy has become caught in a process of declining external competitiveness which is both a consequence and a cause of a deteriorating economic environment characterised by low profits the holding back of new investment and insufficient job opportunities blackaby 1978 hughes 1981 cambridge economic policy group 1982 it is the absolute decline in industrial employ ment sustained now for some sixteen years and accelerated by the current recession that is one of the worrying features of this deindustrialisation from a peak level in 1966 total industrial employment has declined by over four million of which three million is accounted for by jobs lost in manufacturing during the 1970s there were some increases in service employment especially in the public sector which offset the decline in manufac turing jobs but that offsetting trend came to a halt towards the end of the decade over the period 1966 81 service employment increased by just over one million so that the loss of four million jobs in industry has been primarily reflected not by jobs created else where in the economy but by an increase in the army of unemployed of nearly three million industrial unemployment is now more than ten times what it was in 1966 this decline in the demand for labour has been characterised by a number of cyclical phases over the last decade or so cycles in the rate of capital accumulation appear to have become more marked and to have been accompanied by pronounced swings in the financial balance of a large number of firms and industries much of the labour displacement that has occurred during these crises has been concentrated in a single year within the four or five year cycle as in 1967 1971 1975 and in the current recession in 1980 with out doubt this latest downturn is the most severe of the post war period an economic col lapse that has been sharply intensified by the tory government s pursuance of restrictive monetarist policies to combat inflation and a laissez faire approach to the supply side of

portfolio and welfare consequences of debt market dominance the ability to issue debt that pays in units of the domestic good leads a country to accumulate a large and negative net foreign asset position while maintaining a positive position in equity this debt market advantage also helps to explain the weak relationship between the real exchange rate and relative consumption our stylized model matches the key facts about the u s international portfolio the u s real exchange rate and explains nearly 50 of the observed variation in the valuation effects we find that taxing bond market transactions increases the volatility of the exchange rate capital flows and allocations in contrast taxing equity positions stabilizes the exchange rate and capital flows while having little impact on the allocation lastly the paper describes a global solution method for portfolio problems under incomplete markets

agricultural policy market barriers and deforestation the case of mexico s southern yucatan summary this paper examines the linkages between agricultural policies and deforestation in a development frontier of southern mexico focusing on support programs targeted at buffering farmers from structural reforms we argue that local barriers to market participation condition the responsiveness of farmers to program incentives thereby constituting a key channel through which agricultural policies impact the environment an econometric model parameterizes the influence of two programs procampo and alianza para el campo on cultivation consistent with an economic environment characterized by market barriers results suggest that program support even when decoupled from production decisions significantly determines land use and deforestation

financial integration and growth in a risky world abstract we revisit the debate on the benefits of financial integration in a two country neoclassical growth model with aggregate uncertainty the framework accounts simultaneously for gains from a more efficient capital allocation and gains from risk sharing together with their interaction global numerical methods allow for meaningful welfare comparisons gains from integration are quantitatively small even for riskier and capital scarce emerging economies these countries import capital for efficiency reasons before exporting it for self insurance leading to capital flows and growth reversals along the transition this opens the door to richer empirical implications than previously considered in the literature

phasing out the gses we develop a new model of the mortgage market where both borrowers and lenders can default risk tolerant savers act as intermediaries between risk averse depositors and impatient borrowers the government plays a crucial role by providing both mortgage guarantees and deposit insurance underpriced government mortgage guarantees lead to more and riskier mortgage originations as well as to high financial sector leverage mortgage crises occasionally turn into financial crises and government bailouts due to the fragility of the intermediaries balance sheets increasing the price of the mortgage guarantee crowds in the private sector reduces financial fragility leads to fewer but safer mortgages lowers house prices and raises mortgage and risk free interest rates due to a more robust financial sector consumption smoothing improves and aggregate welfare increases while borrowers are nearly indifferent to a world with or without mortgage guarantees savers are substantially better off while aggregate welfare increases so does wealth inequality jel g12 g15 f31

statistical arbitrage with default and collateral abstract this paper studies the implications of the absence of statistical arbitrage opportunities in a two period incomplete market economy where default is allowed but there are collateral requirements modified versions of the fundamental theorem of asset pricing are obtained

collateral constraints and asset prices abstract we study the effects of collateral constraints in an economy populated by investors with nonpledgeable labor incomes and heterogeneous preferences and beliefs we show that these constraints inflate stock prices and generate spikes and crashes in price dividend ratios and volatilities clustering of volatilities and leverage cycles they also lead to substantial decreases in interest rates and increases in sharpe ratios when investors are anxious about hitting constraints due to production crises in the economy furthermore stock prices have large collateral premiums over nonpledgeable incomes we derive asset prices and stationary distributions of the investors consumption shares in closed form

redundancies labour turnover and employment contraction in the recession a regional analysis martin r l 1984 redundancies labour turnover and employment contraction in the recession a regional analysis reg studies 18 445 458 the rapid decline of the british economy during the current recession has generated considerable interest in the geography of employment contraction and the regional incidence of redundancy in this paper it is argued that regional variations in the impact of redundancy need to be viewed in relation to the other labour turnover flows that contribute to net employment loss estimates of gross labour turnover flows suggest that there have been wide differences amongst the regions in the proportion of total discharges accounted for by redundancies furthermore there is evidence that regional specific rates of redundancy are related to 1 the pace of decline in a region 2 the average rate of national job turnover in the region and 3 the extent to which such natural turnover declines as employment opportunities diminish and unemployment rises the implication is

income strategies among rural households in mexico the role of off farm activities abstract off farm activities generate on average more than half of farm households incomes in the mexican ejido sector participation in these activities helps reduce poverty and contributes to greater equality in the distribution of income this paper analyzes the determinants of access to off farm sources of income across households we find that education plays a major role in accessing better remunerated nonagricultural employment adults of indigenous ethnic origin suffer from an educational lag and have less access to off farm nonagricultural employment than non indigenous adults at identical educational levels the regional availability of off farm employment strongly affects participation in addition women are differentially limited by distance to urban centers in their ability to gain off farm employment

convergence of strategic behavior to price taking we address the following issue what can be said about the degree of competition in a set of markets with a large number of participants when no information on the distribution of individual characteristics is available our main result is that the proportion of individuals whose strategic behavior differs substantially from price taking converges to zero as the number of market participants becomes large regardless of the distribution of characteristics

deagrarianization and rural employment in sub saharan africa a sectoral perspective abstract sub saharan africa is steadily becoming less rural in character for decades development thinking has prescribed industrialization as the virtuous path leading away from economic dependence on agriculture but africa s industrial record has been plagued with underperformance an alternative perspective centered on the process of deagrarianization and attendant rural employment generation may offer more explanatory power and policy direction this paper outlines key theoretical components and practical concerns of a deagrarianization approach the nature and incidence of deagrarianization in sub saharan africa is contrasted with that experienced in developed industrial countries conceptual approaches dealing with rural non agricultural employment are identified within different social science disciplines through a thematic review of the literature the conclusion highlights the need for more focused study of the deagrarianization process and rural service sector development

vulnerability income growth and climate change summary cross country data on energy consumption per capita gross domestic product gdp and a social vulnerability index are used to measure changes in vulnerability associated with changes in per capita gdp and per capita energy consumption energy consumption through its non linear effect on per capita income reduces a country s overall vulnerability by a greater amount at moderate incomes than at low or high incomes an implication is that policies aimed at reducing carbon emissions in developing countries are unlikely to significantly affect vulnerability to the risks arising from climate change especially at very low incomes

collateral once again abstract this paper shows how collateral is used to prove the second part of the fundamental theorem of asset pricing in a collateral default setting which connects the concept of an arbitrage free price with the solution of the individual utility maximization problem

asset shortages liquidity and speculative bubbles abstract we study the effect of asset shortages on liquidity in economies with limited enforcement of debt contracts we establish that under a suitable assumption in terms of gains from trade liquidity does not dry up and trading volumes do not disappear as credit conditions worsen the equilibrium outcome becomes arbitrarily close to a purely speculative equilibrium and bubbles occur in the limit the result applies to incomplete markets and more generally to equilibria where collateral constraints interfere with the additivity of the payoff pricing functional

life cycle economies and aggregate fluctuations do the implications for business cycle issues change when we switch from studying infinitely lived representative agent models to more sophisticated demographic structures with finitely lived agents this article addresses that question by using a large overlapping generations model that is calibrated to u s demographic properties microeconomic evidence and national income and product accounts the finding is that the answers obtained are basically the same for the two kinds of models the article also explores the relative volatility of hours across age groups an issue that cannot be addressed by using the infinitely lived representative agent abstraction

recursive equilibrium in stochastic overlapping generations economies we prove the generic existence of a recursive equilibrium for overlapping generations economies with uncertainty generic here means in a residual set of utilities and endowments the result holds provided there is a sufficient number of potentially different individuals within each cohort

rainfall uncertainty and occupational choice in agricultural households of rural nepal abstract although agriculture is the main occupation in rural nepal evidence suggests that households strive to diversify their sources of income this paper investigates why this is the case using household data from the world bank and information on rainfall for the various rural districts of nepal we find that occupational choice is highly correlated to the uncertainty associated with historical rainfall patterns where the head is employed in agriculture other family members are less likely to choose agriculture as an occupation in districts where rain is more uncertain estimates indicate that for a 1 per cent increase in the coefficient of variation of rain there is a 0 61 per cent decrease in the probability of choosing the same occupation as the household head where the head is classified as self employed in agriculture the negative effect of rainfall uncertainty on occupational choice is less evident in households that have access to credit and in households with relatively high levels of

stationary equilibria in asset pricing models with incomplete markets and collateral we consider an infinite horizon exchange economy with incomplete markets and collateral constraints as in the two period model of geanakoplos and zame 2002 households can default on their liabilities at any time and financial securities are only traded if the promises associated with these securities are backed by collateral we examine an economy with a single perishable consumption good where the only collateral available consists of productive assets in this model competitive equilibria always exist and we show that under the assumption that all exogenous variables follow a markov chain there also exist stationary equilibria these equilibria can be characterized by a mapping from the exogenous shock and the current distribution of financial wealth to prices and portfolio choices we develop an algorithm to approximate this mapping numerically and discuss ways to implement the algorithm in practice a computational example demonstrates the performance of the algorithm and shows some quantitative features of equilibria in a model with collateral and default

margin regulation and volatility an infinite horizon asset pricing model with heterogeneous agents and collateral constraints can explain why adjustments in stock market margins under us regulation t had an economically insignificant impact on market volatility in the model raising the margin requirement for one asset class may barely affect its volatility if investors have access to another unregulated class of collateralizable assets through spillovers however the volatility of the other asset class may substantially decrease a very strong dampening effect on all assets return volatilities can be achieved by a countercyclical regulation of all markets