integrating the human sciences to evolve effective policies this paper describes an evolutionary perspective on human development and wellbeing and contrasts it with the model of self interest that is prominent in economics the two approaches have considerably different implications for how human wellbeing might be improved research in psychology prevention science and neuroscience is converging on an evolutionary account of the importance of two contrasting suites of social behavior prosociality vs antisocial behaviors crime drug abuse risky sexual behavior and related problems such as depression prosociality of individuals and groups evolves in environments that minimize toxic biological and social conditions promote and richly reinforce prosocial behavior and attitudes limit opportunities for antisocial behavior and nurture the pursuit of prosocial values conversely antisocial behavior and related problems emerge in environments that are high in threat and conflict over the past 30 years randomized trials have shown numerous family school and community interventions to prevent most problem behaviors and promote prosociality research has also shown that poverty and economic inequality are major risk factors for the development of problem behaviors the paper describes policies that can reduce poverty and benefit youth development although it is clear that the canonical economic model of rational self interest has made a significant contribution to the science of economics the evidence reviewed here shows that it must be reconciled with an evolutionary perspective on human development and wellbeing if society is going to evolve public policies that advance the health and wellbeing of the entire population

reference dependent ambiguity abstract motivated by experimental and empirical evidence i study a framework where reference points such as a status quo endowment or default option can distort the way an individual responds to ambiguity i characterize a model of reference dependent maxmin expected utility and provide behavioral foundations for comparing reference dependent ambiguity attitudes i also illustrate some implications of reference dependent ambiguity for trade in an asset market including underdiversification no trade and the potential for a market collapse

rural wheat consumption in china the share of wheat in china s overall grain production and consumption has increased since economic reform china is also a large wheat importer but imports are erratic in the literature there is disagreement over future prospects for per capita wheat consumption in china and imports most of the wheat is consumed in rural areas where the majority of the population resides and where consumers have shifted from coarse grains and potatoes to wheat we analyze rural wheat consumption using household data from two provinces we find there is evidence to support a contention that china s per capita wheat consumption may not grow very fast in the future and could actually fall

arbitrage and existence of equilibrium in infinite asset markets this paper develops a framework for a general equilibrium analysis of asset markets when the number of assets is infinite such markets have been studied in financial economics in the context of asset pricing theories a distinctive feature of an equilibrium model of asset markets is that investors portfolio choice sets are typically not bounded below we prove that an equilibrium exists under a condition that markets are arbitrage free the markets are arbitrage free if there is a price system under which no investor has an arbitrage opportunity the concept of an arbitrage opportunity used in this paper differs from the standard concept on an arbitrage portfolio in financial markets which is a portfolio that guarantees a non negative payoff in every event a positive payoff in some event and has zero price we provide an extensive discussion of concepts of an arbitrage opportunity

marketed surplus under risk do peasants agree with sandmo using a newly defined notion of aversion to income risk the behavior of the marketed surplus producer under price risk is characterized unlike the familiar case first examined by sandmo output depends on both ordinal preferences for goods and on risk attitudes conditions are found that yield an output level under risk that is smaller than under certainty if these conditions do not hold both risk and risk aversion may have a positive effect on output implications for econometric studies of risk attitudes are considered and illustrated with an example finally we examine the effect of uncertainty on the peasant s long run equilibrium

declining nutrient intake in a growing china does household heterogeneity matter summary this paper uses chinese household data for 1989 2009 to explain why mean nutrient intake has declined despite economic growth we focus on household heterogeneity in nutrient intake response to increases in household income allowing for its endogeneity a quantile instrumental variable fixed effects panel estimation shows that rising income tends to reduce inequality in macronutrient intake in both urban and rural areas in 2004 09 this is driven by increases in nutrient intake for the urban nutrient poor and falls in nutrient intake for the rural nutrient non poor on the other hand fluctuations in prices of meat eggs and oil increase nutrition poverty

asset allocation with distorted beliefs and transaction costs abstract in this paper we study the problem of the optimal portfolio selection with transaction costs for a decision maker who is faced with knightian uncertainty the decision maker s portfolio consists of one risky and one risk free asset and we assume that the transaction costs are proportional to the traded volume of the risky asset the attitude to uncertainty is modeled by the choquet expected utility we derive optimal strategies and bounds of the no transaction region for both optimistic and pessimistic decision makers the no transaction region of a pessimistic investor is narrower and its bounds lie closer to the origin than that of an optimistic trader moreover under the choquet expected utility the structure of the no transaction region is not necessarily a closed interval as it is under the standard expected utility model

distributional impacts of a local living wage increase with ability sorting abstract i develop a model of ability sorting of low wage workers across multiple markets when one market substantially increases its wage floor using a living wage the wage floor increase can increase or decrease employment probabilities in both covered and uncovered markets

investment in new activities and the welfare cost of uncertainty abstract recent literature has shown that trade distortions are associated with first order costs stemming from the induced drop in the formation of new activities we demonstrate that uncertainty may induce similar welfare costs and that these costs apply also to a closed economy this argument is illustrated in romer s model of a dependent economy where foreign direct investment is needed to enable the importation of capital goods and intermediate products used in domestic production we show that knightian uncertainty inhibits the formation of new activities leading to first order losses whereas risk aversion alone leads to second order losses

ambiguity and uncertainty in ellsberg and shackle this paper argues that the similarities between ellsberg s and shackle s frameworks for discussing the limits of the probabilistic approach to decision theory are more important than usually admitted the paper discusses the grounds on which the ambiguity surrounding the decision maker in ellsberg s urn experiments can be deemed analogous to the uncertainty faced by shackle s entrepreneur taking crucial decisions the two authors insights are assessed and special attention is paid to the criteria for decision under uncertainty they put forward the paper establishes a link between ellsberg s and shackle s perspectives and the non additive probability approach of gilboa and schmeidler an approach that offers an alternative to standard probability calculus which can be of use to analyse both ambiguity and uncertainty the comparison between ellsberg and shackle draws on an interpretation of keynes s treatise on probability emphasising keynes s rejection of both well defined probability functions and maximisation as a guide to human conduct it is shown that keynes s viewpoint implies a reconsideration of the boundaries of probability theory that is in the same vein of ellsberg s and shackle s concern in the years of the consolidation of savage s new probabilistic mainstream copyright the author 2009 published by oxford university press on behalf of the cambridge political economy society all rights reserved oxford university press

arbitrage bubbles and valuation the standard present value rule of asset pricing may fail in financial markets when infinitely many assets can be traded i provide an example of asset payoffs and prices such that prices are arbitrage free and could be equilibrium prices in frictionless markets using valuation theory methods i show that asset prices can be meaningfully decomposed into a fundamental value and a pricing bubble the fundamental value obeys the present value rule

detecting money market bubbles the existence of a self financing trading strategy that replicates the money market account at a fixed future date at a lower cost than the current value of this account constitutes a money market bubble mmb understanding whether a market exhibits an mmb is crucial in particular for derivative pricing an mmb precludes the existence of a risk neutral probability measure the benchmark approach allows to study mmbs and is formulated under the real world probability measure it does not require the existence of a risk neutral probability measure using a range of well known stochastic volatility models we study the existence of an mmb in the us economy and find that the us market exhibits an mmb for all models considered that allow it this suggests that for derivative pricing and hedging care should be taken when making assumptions pertaining to the existence of a risk neutral probability measure less expensive portfolios are likely to exist for a wide range of long term derivatives as typical for pensions

a policy analysis of china s wheat economy this paper examines the impacts of china s historical and anticipated future reforms on its domestic wheat economy and how it affects the import demand for wheat using a stochastic coefficient regression method the results strongly support the hypothesis that producers and consumers in the post reform era were responsive to a less controlled economy furthermore the higher import forecasts indicate that china will interact more with the world wheat market

on booms that never bust ambiguity in experimental asset markets with bubbles we study the effect of ambiguity on the formation of bubbles and on the occurrence of crashes in experimental asset markets a la smith suchanek and williams 1988 we extend their framework to an environment where the fundamental value of the asset is ambiguous we show that when the fundamental value is ambiguous asset prices tend to be lower than when it is risky although bubbles form in both the ambiguous and the risky environments additionally bubbles do not crash in the ambiguous case whereas they do so in the risky one these findings regarding depressed prices and the absence of crashes in the presence of ambiguity are in line with recent theoretical work stressing the crucial role of ambiguity to account for surprisingly low equity prices high returns as well as herding in asset markets

iq and stock market participation stock market participation is monotonically related to iq controlling for wealth income age and other demographic and occupational information the high correlation between iq and participation exists even among the affluent supplemental data from siblings studied with an instrumental variables approach and regressions that control for family effects demonstrate that iq s influence on participation extends to females and does not arise from omitted familial and nonfamilial variables high iq investors are more likely to hold mutual funds and larger numbers of stocks experience lower risk and earn higher sharpe ratios we discuss implications for policy and finance research

model misspecification and underdiversification in this paper we study intertemporal portfolio choice when an investor accounts explicitly for model misspecification we develop a framework that allows for ambiguity about not just the joint distribution of returns for all stocks in the portfolio but also for different levels of ambiguity for the marginal distribution of returns for any subset of these stocks we find that when the overall ambiguity about the joint distribution of returns is high then small differences in ambiguity for the marginal return distribution will result in a portfolio that is significantly underdiversified relative to the standard mean variance portfolio

arbitrage and the existence of competitive equilibrium a general equilibrium model of markets for commodities and assets is considered the author develops the notion of a price system that admits no arbitrage opportunity and demonstrates the fundamenta l role of this concept for the theory of the existence of a competiti ve equilibrium a price system admits no arbitrage opportunity for a consumer if every bundle of desired commodities has a positive market value the author proves that the existence of a price system that a dmits no arbitrage opportunity for all consumers is sufficient for th e existence of an equilibrium copyright 1987 by the econometric society

rice in asia is it becoming an inferior good empirical results using time series and cross sectional data indicate that rice in asia is becoming an inferior good income elasticities declined and in some cases became negative between 1961 and 1985 in most of the fourteen asian countries studied accordingly domestic demand for rice in these countries is not likely to grow as rapidly as it has in the past as a consequence there is a potential for excess supplies of rice to develop in asia putting downward pressure on rice prices while governments in asian countries may need to adjust their rice policies in the future world rice suppliers may need to develop new markets for rice

liquidity and asset market dynamics this study analyzes economies with an essential role for liquid assets in the exchange process the model can generate multiple stationary equilibria across which asset prices market participation capitalization output and welfare are positively related it can also generate a variety of nonstationary equilibria even when fundamentals are deterministic and time invariant including periodic chaotic and stochastic sunspot equilibria with recurrent market crashes some equilibria have asset price trajectories that resemble bubbles growing and bursting endogenous private and public liquidity is also introduced sometimes it is efficient to provide enough liquid assets to satiate demand other times it is not

ambiguity models and the machina paradoxes daniel ellsberg 1961 constructed counterexamples to show the limitations of leonard j savage s 1954 subjective expected utility seu ellsberg s examples involved a comparison between objective uncertainty risk in which probabilities are known and subjective uncertainty in which they are not the prevailing prefer ence for objective over subjective uncertainty known as ambiguity aversion raised an important paradox for economic theory since ellsberg s classical work many models have been developed to generalize seu in order to accommodate the pref erence for objective over subjective uncertainty in the same manner as ellsberg mark j machina 2009 proposed two examples that falsify one of the seu generalizations david schmeidler s 1989 choquet expected utility ceu this article shows that the impact of machina s examples is not restricted to the model initially targeted his examples pose difficulties not only for ceu but also for the four other most popular and widely used models of ambiguity averse preferences namely maxmin expected utility itzhak gilboa and schmeidler 1989 variational preferences fabio maccheroni massimo marinacci and aldo rustichini 2006 a maxmin paolo ghirardato maccheroni and marinacci 2004 and the smooth model of ambiguity aversion peter klibanoff marinacci and sujoy mukerji 2005 consequently the implications for economics are more pro found than initially thought we also discuss marciano siniscalchi s 2009 vector expected utility veu model which can account for the typical ambiguity averse preferences in machina s examples finally we examine how our results are related to the uncertainty aver sion axiom which is assumed in virtually all commonly used decision models under ambiguity in particular we argue that machina s examples demonstrate that the uncertainty aversion axiom can be overly restrictive in some circumstances the article proceeds as follows section i presents the four models of ambiguity averse preferences which are alternatives to ceu and which are examined in this paper in section ii and iii the implications of machina s examples for these models are presented section iv discusses alternative models and the uncertainty aversion axiom

stochastic dominance pareto optimality and equilibrium asset pricing pricing a factor subspace contains the market portfolio and is such that every marketed contingent claim is second order stochastically dominated by a claim from the factor subspace conditions are given for the existence of equilibrium and it is shown how apt and capm can be interpreted in the framework of the paper if sufficiently many call options on the market portfolio are traded then the space spanned by these options can be used as the factor subspace we consider markets in which a collection of financial assets are traded the collection may be finite or infinite markets are frictionless and short sales of assets are permitted asset payoffs are random variables which are elements of a space of contingent claims by forming portfolios of the marketed assets payoffs in a certain linear subspace of the space of all contingent claims can be attained we call this subspace a space of marketed claims we say that a closed subspace of the space of marketed claims is a factor subspace if two conditions are satisfied first the market portfolio payoff i e the payoff of an aggregate endowment of portfolios per capita belongs to this subspace second every marketed contingent claim is dominated in the sense of second order stochastic dominance by some contingent claim in the factor subspace we demonstrate that for each asset market economy there is a well defined minimal factor subspace in the sense that no proper subspace of it can be a factor subspace if markets are complete i e if a full set of arrow securities are traded then the price of any given asset can be expressed in terms of prices of arrow securities or state prices breeden and litzenberger 1978 have shown that state prices can be replaced by the values of options thus in a complete market asset prices are determined either by state prices or call options it is established in this paper that these ideas and methods are applicable to asset pricing theories even when markets are incomplete making use of the argument of second order stochastic dominance we show that every constrained pareto optimal portfolio allocation consists exclusively of portfolios which generate the factor subspace the same holds for an equilibrium portfolio allocation thus for an economy with a factor subspace only a partial set of arrow securities which is large enough to generate the factor subspace is required to price assets this paper establishes that there exists an equilibrium in which the price of a portfolio equals the price of the dominating portfolio with the same expected return in the factor subspace since the dominating

quantifying the structure of food demand in china an econometric approach this article examines food demand structure and its dynamics for 11 commodities in urban china the analysis is based on household level expenditure survey data for two cross sectional surveys of chinese households pertaining to food expenditure patterns during 1995 and 2003 pre committed components of commodity demands that are insensitive to economic variables are explored we use the generalized quadratic almost ideal demand system gqaids for its empirical superiority to the generalized almost ideal demand system gaids and estimate the associated parameters via full information maximum likelihood procedure fiml accounting for endogeneity of total expenditures on food for home consumption fah we also use quality adjusted commodity unit values to control for quality differences resulting from commodity aggregation and food choice furthermore we derive gqaids elasticity formulas and estimate income elasticities without restrictions the results partially support the hypothesis that an average chinese household has incorporated elements of western diet fine grains into traditional chinese food diet over time moreover the outcome of a simple test developed here points to possible preference changes for a majority of food staples under study

on fragility of bubbles in equilibrium asset pricing models of lucas type abstract in this paper we study the existence of bubbles for pricing equilibria in a pure exchange economy a la lucas with infinitely lived homogeneous agents the model is analyzed under fairly general assumptions no restrictions either on the stochastic process governing dividends distribution or on the utilities possibly unbounded are required we prove that the pricing equilibrium is unique as long as the agents exhibit uniformly bounded relative risk aversion a generic uniqueness result is also given regardless of agent s preferences a few pathological examples of economies exhibiting pricing equilibria with bubble components are constructed finally a possible relationship between our approach and the theory developed by santos and woodford on ambiguous bubbles is investigated the whole discussion sheds more insight on the common belief that bubbles are a marginal phenomenon in such models journal of economic literature classification numbers c61 c62 d51 g12

do living wage ordinances reduce urban poverty living wage ordinances typically mandate that businesses under contract with a city or in some cases receiving assistance from a city must pay their workers a wage sufficient to support a family financially we estimate the effects of these ordinances on wages hours and employment in cities that have adopted such legislation we then examine the effects of these laws on poverty our findings indicate that living wage ordinances boost wages of low wage workers moreover we find a moderate negative employment effect finally some of the evidence suggests that living wages achieve modest reductions in urban poverty

are there rational bubbles in foreign exchange markets evidence from an alternative test abstract this paper employs the kalman filter technique to estimate and test for stochastic bubbles for exchange rates between the us dollar and the british pound the japanese yen and the deutsche mark i find no significant evidence of bubbles my results are in sharp contrast with previous findings on exchange rate bubble testing and cast some doubt on those claims that the dollar exchange rates were driven by speculative bubbles in the post bretton woods period

increasing returns in infinite horizon economies this paper shows that in a general equilibrium model with an infiniite holizonl in whichi productionl may exhibit increasing returns to scale or non conivexities marginal cost pricing equilibria exist anid are essential that is stable witlh respect to small perturbationis of the economily as in many important models of mairket imperfections marginal cost pricinig equilibria need not be pareto optimal in the presence of noni convexities so the systematic approaches to equilibrium analysis in infinite dimenisionial commodity spaces which rely crucially oln the first welfare theorem cainnot be used instead this paper introduces leray schauder degree theory the extension of degree theor y to banacih and locally convex spaces as the natural methodology for showinlg that equilibria exist and for anialyzing qualitative features of equilibria such as local uniqueness or essentiality

rational asset pricing bubbles this paper provides a fairly systematic study of general economic conditions under which rational asset pricing bubbles may arise in an intertemporal competitive equilibrium framework our main results are concerned with nonexistence of asset pricing bubbles in those economies these results imply that the conditions under which bubbles are possible including some well known examples of monetary equilibria are relatively fragile this paper is concerned with the conditions under which asset prices in an intertemporal competitive equilibrium are equal to the present value of the streams of future dividends to which each asset represents a claim according to a central result of the theory of finance this is very generally true in the case of economies with trading at only a finite sequence of dates as long as there are no restrictions upon transactions other than that associated with possible incom pleteness of the set of securities that are traded the result is sometimes called the fundamental theorem of asset pricing here we consider the extent to which such a result continues to be valid in the case of trading over an infinite horizon it has often been observed in the econometric literature on asset pricing bubbles that it is possible in principle for the price of a perpetuity and the dividends on that security to satisfy at all times a present value relation for one period holding returns while the security s price nonetheless does not equal the present value of the stream of dividends expected over the infinite future in such a case the price of the perpetuity is said to involve a bubble component 2 joint stochastic processes for which this component is nonzero are sometimes argued to characterize existing assets for a recent example see froot and obstfeld 1991 but such an inference depends upon aspects of the stochastic

confidence and the real value of money in an overlapping generations economy we demonstrate that stochastic bubbles which have a constant exogenous probability of collapsing may exist in general equilibrium on an intrinsically useless and unbacked asset money this may happen provided that the probability q that the bubble will persist next period is large enough and exceeds a threshold level q which we call the minimum rate of confidence this condition is always violated when the economy without bubble is dynamically efficient it is more likely to be satisfied in dynamically inefficient economies the larger the size of the inefficiency as measured by the excess of the growth rate over the no bubble interest rate we study both exchange and production economies

opaque trading disclosure and asset prices implications for hedge fund regulation we construct a rational expectations equilibrium model to investigate the effect of ambiguity about hedge fund strategies on market efficiency and aggregate welfare in our model some traders mutual funds view the equilibrium trading strategies of other traders hedge funds as ambiguous this ambiguity limits the ability of mutual funds to infer information from prices and affects the market performance we use this analysis to investigate the implications of regulations that affect the amount of ambiguity about hedge fund strategies or the cost of operating a hedge fund our analysis demonstrates how regulations affect asset prices and welfare through their influence on opaque trading

living wages protection for or protection from low wage workers living wage laws are touted as anti poverty measures yet they apply to only a small fraction of workers most commonly covering only employers with city contracts the apparent contradiction between broad anti poverty goals and narrow coverage suggests that goals other than poverty reduction may partly underlie living wage campaigns this paper considers the hypothesis that living wage laws act to maintain or increase rents among unionized municipal workers by raising the wages that city contractors would have to pay living wage laws may reduce the incentives for cities to contract out work that would otherwise be done by unionized municipal employees hence increasing the bargaining power of municipal unions and leading to higher wages for their members the evidence presented here from an analysis of cps data for 1996 2000 indicates that the wages of unionized municipal workers are indeed increased as a result of living wage laws covering contractors

food scares in an uncertain world we develop a model that explains the stylized facts of food scares an immediate and sharp decline in consumption of the product followed by a slow and frequently partial recovery of demand after the scare passes the model is used in conjunction with the natural experiment afforded by the mad cow crisis to elicit empirical information on decision makers perception of uncertainty our theoretical and quantitative results suggest that observed behavior is consistent with sharp changes in beliefs and the presence of knightian uncertainty as measured by the degree of imprecision in our model

a unified beta pricing theory abstract this paper derives ross s mutual fund separation theory and a new equilibrium version of ross s arbitrage pricing theory as special cases of a general theory the paper also reveals that the two theories are identical in their predictions of asset prices and portfolio returns the capital asset pricing model a restricted case of the mutual fund separation theory receives special treatment

quasi equilibria for growth economies abstract we find preferences that discount utility from future consumption yet violate the standard growth condition in representative agent endowment economies such economies have no competitive equilibria but have quasi equilibria the supporting price systems include a type of speculative bubble

diversification and equilibrium in securities markets abstract diversification is the strategy of investing small fractions of wealth in each of a large number of securities and thereby reducing risk the basic argument in support of diversification is an appeal to the law of large numbers a portfolio in which an investor s wealth is invested in equal fractions in each ofnsecurities with i i d returns has a return that converges to a riskless return asnincreases indefinitely any risk averse investor would prefer the limit riskless return to the return of any portfolio in this paper we use the space ba of all finitely additive signed measures on the set of natural numbers the index set for securities to model the set of portfolios from which an investor may choose this portfolio space contains arbitrary finite portfolios and a nontrivial portfolio which is the limit of the sequence of portfolios having the fraction of wealth 1 ninvested in each ofnsecurities we identify a class of portfolios which we call perfectly diversified these portfolios are described by purely finite additive measures in a perfectly diversified portfolio wealth invested in each individual security is a negligible fraction of the total wealth of the portfolio we show that the return of every perfectly diversified portfolio of securities with uncorrelated returns is riskless it is shown that modeling of the portfolio space as the space ba makes possible a rigorous derivation of a general equilibrium version of the arbitrage pricing theorem apt the apt provides a good illustration of the implications of diversification for equilibrium prices of securities journal of economic literatureclassification numbers d52 g20

the market for sweepstakes this paper studies the market for monopolistically supplied sweepstakes we derive equilibrium demands for fixed prize and variable prize sweepstakes and determine the profit maximizing prize level and pay out ratio respectively it can be profitable to offer each type of sweepstake when there is a large enough number of weighted utility consumers who have constant absolute risk attitudes are strictly averse to small as well as symmetric risks and display longshot preference behaviour moreover for the variable prize sweepstake the supplier will generally find it profitable to combine sweepstakes targeting two smaller populations and offer a single sweepstake to the combined population this implication is corroborated by the recent spate of mergers of smaller state lotteries into larger ones

applying regret theory to investment choices currency hedging decisions we apply regret theory an axiomatic behavioral theory to derive closed form solutions to optimal currency hedging choices investors experience regret of not having chosen the ex post optimal hedging decision hence investors anticipate their future experience of regret and incorporate it in their objective function we derive a model of financial decision making with two components of risk traditional risk volatility and regret risk we find results that are in sharp contrast with traditional expected utility loss aversion or disappointment aversion theories we discuss the empirical implications of our model and its ability to explain observed hedging behavior

general equilibrium wariness and efficient bubbles abstract wary consumers overlook gains but not losses in remote sets of dates or states as preferences are upper but not lower mackey semi continuous bewley s 1972 4 result on existence of equilibrium whose prices are not necessarily countably additive holds wariness is related to lack of myopia and to ambiguity aversion and therefore to bewley s 1986 6 work on knightian uncertainty wary infinite lived agents have weaker transversality conditions allowing them to be creditors at infinity and for bubbles to occur in positive net supply assets completing the markets there are efficient allocations that can only be implemented with asset bubbles

arbitrage martingales and bubbles abstract viability of security prices implies linear valuation of payoffs but if there exist an infinite number of securities or trading dates does not imply the existence of a risk neutral probability since countable additivity may fail an example is given

optimism and pessimism in games this paper considers the impact of ambiguity in strategic situations it extends the earlier literature by allowing for optimistic responses to ambiguity ambiguity is modelled by ceu preferences we propose a new solution concept for players who may express ambiguitypreference then we study comparative statics of changes in ambiguity attitude in games with strategic complements this gives a precise statement of the impact of ambiguity on economic behaviour

the effects of living wage laws evidence from failed and derailed living wage campaigns abstract living wage campaigns have succeeded in about 100 jurisdictions in the united states but have also been unsuccessful in numerous cities these unsuccessful campaigns provide a better control group or counterfactual for estimating the effects of living wage laws than the broader set of all cities without a law and also permit the separate estimation of the effects of living wage laws and living wage campaigns we find that living wage laws raise wages of low wage workers but reduce employment among the least skilled especially when the laws cover business assistance recipients or are accompanied by similar laws in nearby cities

sequential two player games with ambiguity if players beliefs are strictly non additive the dempster shafer updating rule can be used to define beliefs off the equilibrium path we define an equilibrium concept in sequential two person games where players update their beliefs with the dempster shafer updating rule we show that in the limit as uncertainty tends to zero our equilibrium approximates bayesian nash equilibrium by imposing context dependent constraints on beliefs under uncertainty

on the different notions of arbitrage and existence of equilibrium in this paper we first prove an equilibrium existence theorem for finite dimensional economies with unbounded below consumption sets we only assume that the individually rational utility set is compact and use the demand approach instead of the standard negishi s approach we next compare the different concepts of no arbitrage that have been used in the literature and give conditions for equivalence between absence of arbitrage and existence of equilibrium lastly we introduce the concept of strong unbounded arbitrage and show that the absence of strong unbounded arbitrage implies the compactness of the individually rational utility set journal of economic literature classification numbers c62 d50

the impact of the minimum wage on other wages in this paper i explore how changes in the minimum wage affect various occupational wages i postulate that other wages increase for two reasons first firms try to mitigate the deterioration in a worker s relative wage which would cause him to reduce his work effort and second there is an increase in the demand for nonminimum wage workers wage adjustment patterns are examined to ascertain whether wage comparisons play a role in the adjustment process the empirical work shows a short run wage compression among white collar occupations which is consistent with the wage comparison model however large standard errors make inferences weak

bubbles and constraints on debt accumulation it is commonly thought tirole econometrica 50 1982 1163 1182 that bubbles cannot occur in deterministic sequential market economies with a finite number of infinitely lived agents this paper shows that the constraint on debt accumulation which make possible the existence of equilibrium can cause bubbles if agents face a wealth constraint bubbles can exist if and only if the assest is in zero net supply if agents face exogenous short sales constraints bubbles can exists if and only if some agent s endowment grows at a rate larger than the rate of return and the short sales constraint binds that agent infinitely often

bubbles and charges the definitions of fundamental value and speculative bubbles that are standard in macroeconomics and finance are given formal representations as the countably additive part and the purely finitely additive part a measure and a pure charge respectively of the supporting price system when the commodity space is lx examples illustrate that rational bubbles can occur in standard general equilibrium models with complete markets and a finite number of agents even in the absence of uncertainty consider an economy which includes securities or capital goods which are claims to cash flows over countably infinite time and also includes markets for all goods conduct the following thought experiment for each security add the present value of the first n elements of the cash flow and take the limit as n gets large this limit represents the fundamental value of the security the difference if any between the price of the security and its fundamental value is termed a speculative bubble this use of the terms fundamental and speculative bubble is we believe one of those that are generally accepted blanchard and fischer 1989 pp 218 221 for example used the terms precisely in this way yet confusion persists about what factors generate bubbles fads and irrationality have always figured prominently and the hypothesis that these factors are important has gained some empirical support from the literature on asset price volatility another bubbleproducing factor is the structure of information in the market in a partialequilibrium setting allen and gorton 1988 showed that rational bubbles can exist with a finite number of agents who have asymmetric information although fads and asymmetric information can undeniably produce bubbles here we focus exclusively on the phenomenon of speculative bubbles in general equilibrium models with optimizing agents rational expectations and symmetric information an important source of confusion we believe is that the term fundamental is used in connection with sunspot equilibria as well as bubble equilibria a sunspot equilibrium is one in which prices and allocations depend on irrelevant sunspots as well as exogenous variations in fundamentals preferences technology and endowments bubbles on this usage reflect the effect of extrinsic uncertainty on equilibrium prices and allocations this use of the term fundamental in connec

existence of equilibrium in capm abstract in the mean variance capital asset pricing model capm non monotonicity of preferences may lead to satiation and short selling as well as satiation may lead to non existence of equilibrium this paper identifies several sets of sufficient conditions for equilibrium to exist the nature of the central conditions is to impose bounds on the investors degree of risk aversion as measured by the marginal rate of substitution between mean and standard deviation of return these bounds do not need to hold globally but only in a relevant range of portfolios or combinations of mean and standard deviation