the effect of annuity insurance on savings and inequality this paper examines the amount of precautionary savings and wealth inequality arising from life span uncertainty by comparing saving behavior under perfect insurance arrangements with that arising under imperfect arrangements namely when longevity risk can be pooled only with members of one s own family the central findings of the paper are that 1 perfecting insurance arrangements can sharply lower savings in both intergenerationally altruistic and life cycle economies and that 2 in altruistic economies perfecting annuity insurance can greatly influence inequality indeed in the long run in our model switching from imperfect family insurance to perfect insurance can mean the difference between absolute inequality and absolute equality

the effect of annuity insurance and savings and inequality this paper examines the amount of precautionary savings and wealth inequality arising from life span uncertainty by comparing saving behavior under perfect insurance arrangements with that arising under imperfect arrangements namely when longevity risk can be pooled only with members of one s own family the central findings of the paper are 1 perfecting insurance arrangements can lower savings in intergenerationally altruistic and life cycle economies and 2 in altruistic economies perfecting annuity insurance can influence in equality indeed in the long run in the model switching from imperfect family insurance to perfect insurance can mean the difference between absolute inequality and absolute equality copyright 1986 by university of chicago press

signaling quality with a money back guarantee the role of transaction costs direct marketing is witnessing explosive growth as consumers increasingly purchase products from their homes their ability to judge the quality of products they buy is significantly reduced in this paper we study how money back guarantees can signal product quality in such environments we interpret product quality broadly to mean both the level of attributes promised as well as the firm s consistency in delivering on those promises key aspects of our formulation are the explicit consideration of transaction costs and alternative signals of product quality transaction costs are the costs the seller or buyer faces when redeeming a money back guarantee we show that money back guarantees signal quality by exploiting the higher probability of returns for a lower quality product and the attendant higher transaction costs however if the seller s transaction costs are very large then there are less costly ways to signal namely charging a high price we compare the signaling performance of 1 price 2 price with uninformative advertising and 3 price with a money back guarantee whereas uninformative advertising does not work at all in our model under certain conditions a money back guarantee is necessary to signal and under other conditions a money back guarantee is a useful supplement to price

planning under incomplete information and the ratchet effect abstract central planning of production is usually performed under asymmetric information the firm in general has more information about its productive possibilities than the central planner from now on for short cp this justifies the use of incentives schemes in which the cp does not directly fix activity levels casual observation of such existing schemes suggests that the time dimensions is crucial for their working typically the cp revises the incentive scheme over time to take into account the information provided by the firm s performance managers of centrally planned economies as well as economists have long recognized that this revision induces firms to underproduce in order to avoid demanding schemes in the future this is the ratchet effect it is purpose of the present paper to study the ratchet effect under the non commitment assumption which we believe to be more realistic the inadequacy of conceptual tools made if difficult in the past to consider such an assumption now basic research on dynamic games with incomplete information recently resulted in new ideas which look particularly relevant for a theoretical analysis of the problem

group loyalty and the taste for redistribution interpersonal preferences preferences that depend on the characteristics of others are typically hard to infer from observable individual behavior as an alternative approach this paper uses survey data to investigate interpersonal preferences i show that self reported attitudes toward welfare spending are determined not only by financial self interest but also by interpersonal preferences these interpersonal preferences are characterized by a negative exposure effect individuals decrease their support for welfare as the welfare recipiency rate in their community rises and racial group loyalty individuals increase their support for welfare spending as the share of local recipients from their own racial group rises these findings help to explain why levels of welfare benefits are relatively low in racially heterogeneous states

trading on inside information evidence from the share structure reform in china abstract we examine stock trading activities in days before chinese listed firms made public announcement to start share structure reform there is significant evidence that relative to a benchmark period institutional investors bought more event firms shares in the last two trading days prior to announcement randomization tests show significant differences in institutional trading activities between event firms and matched control firms which suggests that some institutions had inside information moreover large trades account for a significant proportion of daily stock price changes in the last 2 days the evidence is consistent with the prediction by holden and subrahmanyam 1992 that when multiple informed investors acquire the same piece of information they will trade aggressively we also find that over the reform period the median share value change of event firms is 6 higher than that of control firms our findings have important implications for enforcement of insider trading regulations in china

insider trading investment and liquidity a welfare analysis we compare equilibrium trading outcomes with and without participation by an informed insider assuming inflexible ex ante aggregate investment choices by agents noise trading arises from aggregate uncertainty regarding other agents intertemporal consumption preferences the welfare levels of outsiders can thus be ascertained the allocations without insider trading are not ex ante pareto efficient because our model differs from standard ones with negative exponential utility functions and normal returns we characterize the circumstances under which the revelation of payoff relevant information via prices arising from insider tradingbenefits outsiders with stochastic liquidity needs by improving risk sharing among them in models of informed trading allen 1984 dennert 1992 grossman and stiglitz 1980 kyle 1985 leland 1992 repullo 1994 it has been customary in order not to have an unrealistic fully revealing rational expectation equilibrium ree and no profits for informed traders to postulate some portion of the market demand for securities as arising from unmodeled noise traders whose endowments and preferences for consumption are left unspecified this makes it difficult to reach a welfare judgment regarding the impact of insider trading even when the implications for the informativeness of asset prices and investment can be ascertained thus an important issue in financial regulatory policy regarding the desirability of allowing trading by asymmetrically informed corporate insiders remains largely unresolved at the conceptual level our major goal in this paper is to rectify this shortcoming by modeling both noise traders and rational a priori uninformed traders together as agents with well specified preferences these agents allocate their endowments across a risky long term and a riskless short term investment ex ante london school of economics and political science and cepr and universita degli studi di torino respectively we are grateful for financial support from the ente einaudi the italian murst and the international centre for economic research icer torino it is a pleasure to acknowledge the excellent research assistance of giacomo elena work on this paper was begun while bhattacharya was a visiting fellow at icer during the summer of 1995 we wish to thank without implicating in errors gabriella chiesa and jose marin for advice and encouragement and participants at seminars at the universities of brescia roma tor vergata tilburg torino the cepr conference on information financial intermediation and the macroeconomy alghero 1997 as well as an anonymous referee and the editor rene stulz for their very helpful comments and suggestions

optimal taxes without commitment abstract in the problem of optimal taxation in an economy with labor and capital the optimal solution when the government can commit to a sequence of tax rates entails that the tax on capital tends to zero in the limit with all the tax burden on labor it is well known however that this solution is time inconsistent so if the commitment power is not perfect this second best tax plan will not be sustainable we model explicitly the trade off between the cost of revising the tax plan and the benefit of the revision as a result when commitment is not possible both the limit tax rate and the steady state capital are different from their levels in the second best solution limit taxes on capital may be strictly positive but it may also be the case that the only sustainable plan has subsidies to capital the subsidies induce an overaccumulation of capital which becomes a commitment device against revisions of the tax plan journal of economic literature classification numbers h21 c73

the strategic bequest motive although recent research suggests that intergenerational transfers play an important role in aggregate capital accumulation our understanding of bequest motives remains incomplete we develop a simple model of strategic bequests in which a testator influences the decisions of his beneficiaries by holding wealth in bequeathable forms and by conditioning the division of bequests on the beneficiaries actions the model generates falsifiable empirical predictions that are inconsistent with other theories of intergenerational transfers we present econometric and other evidence that strongly suggests that bequests are often used as compensation for services rendered by beneficiaries

subjective performance measures in optimal incentive contracts objective measures of performance are seldom perfect in response incentive contracts often include important subjective components that mitigate incentive distortions caused by imperfect objective measures this paper explores the combined use of subjective and objective performance measures in respectively implicit and explicit incentive contracts naturally objective and subjective measures often are substitutes sometimes strikingly so we show that if objective measures are sufficiently close to perfect then no implicit contracts are feasible because the firm s fallback position after reneging on an implicit contract is too attractive we also show however that objective and subjective measures can reinforce each other if objective measures become more accurate then in some circumstances the optimal contract puts more weight on subjective measures because the improved objective measures increase the value of the ongoing relationship and so reduce the firm s incentive to renege we also analyze the use of subjective weights on objective performance measures and provide case study evidence consistent with our analyses

credit markets in northern nigeria credit as insurance in a rural economy this article addresses the issues of imcomplete markets and imperfect information in the context of credit markets in rural northern nigeria in much recent theoretical literature the problems of moral hazard and adverse selection are assumed to be decisive for the organization of agrarian institutions in contrast it is found that in the four villages surveyed credit transactions take advantage of the free flow of information within rural communities information asymmetries between borrower and lender are unimportant and their institutional consequences the use of collateral and interlinked contracts are absent credit transactions play a direct role in pooling risk between households through the use of contracts in which the repayment owed by the borrower depends on the realization of random production shocks by both the borrower and the lender

the role of targeted communication and contagion in product adoption the two main influences leading to adoption at the individual consumer level are marketing communication and interpersonal communication although evidence of the effect of these two influences is abundant at the market level there is a paucity of research documenting the simultaneous effect of both influences at the individual consumer level thus the primary objective of this paper is to fill the gap in the literature by documenting the existence and magnitude of both influences at the individual customer level while controlling for unobserved temporal effects the pharmaceutical industry provides an appropriate context to study this problem it has been conjectured that adoption and usage patterns of a new drug by physicians contagion acts as a consumption externality as it allows a given physician to learn about the efficacy and use of the drug in addition pharmaceutical companies target individual physicians via marketing activities such as detailing sampling and direct to consumer adverti

the crowding out effect of formal insurance on informal risk sharing an experimental study abstract this paper investigates the crowding out effect of formal insurance on informal risk sharing arrangements via theory and laboratory experiment our model and simulation predict that the crowding out of private transfers is often more than one for one and will reduce the total risk coverage furthermore the existence of a moderate degree of altruism exaggerates the crowding out effect especially when there is an ex ante income inequality these predictions are mostly supported by the laboratory experiment except that the crowding out effect is not more than one for one and hence the total risk coverage is not significantly reduced by formal insurance

unemployment insurance and labor contracts under asymmetric information theory and facts the paper provides evidence to show that many u s labor contracts havelittle or no private unemployment insurance provision a model of an optional contract under asymmetric information with no private unemployment insurance is presented underemployment and involuntaryunemployment may coexist copyright 1986 by american economic association

the family as an incomplete annuities market families can self insure against uncertain dates of death through implicit or explicit agreements with respect to consumption and interfamily transfers interfamily transfers need have nothing to do with altruistic feelings they may simply reflect risk sharing behavior of completely selfish family members although family annuity markets are incomplete even small families can substitute by more than 70 percent for perfect market annuities given adverse selection and transaction costs family risk pooling may be preferred to public market annuities in the absence of public annuities these risk sharing arrangements provide powerful incentives for marriage and family formation

marriage divorce and reciprocity based cooperation this paper considers partnership formation partnership dissolution and reciprocity based cooperation by couples in the form of voluntary transfers to smooth consumption while risk sharing is one benefit of having a partner it is also limited by the endogenous risk of separation the equilibrium formation and dissolution of partnerships are determined simultaneously with cooperative behavior publicly provided earnings insurance is shown to increase the turnover rate in the marriage market as well as to reduce the steady state marriage rate and the implicit financial cooperation between partners

moral hazard and nonmarket institutions dysfunctional crowding out or peer monitoring the authors examine a situation in which insurance is characterized by moral hazard when market insurance is provided supplementary mutual assistance between family and friends unobservable to market insurers will occur when nonmarket insurers have no better information than market insurers the mutual assistance not only crowds out market insurance but is also harmful and therefore dysfunctional alternatively when nonmarket insurers can observe each other s effort perfectly mutual assistance is beneficial these results point to the potential importance of peer monitoring mechanisms in mitigating moral hazard copyright 1991 by american economic association

investment and insider trading within a dynamic environment this paper introduces an inside trader to an economy where rational but uninformed traders choose between investment projects with different levels of insider trading when inside information has little value in future investment decisions insider trading distorts investment towards assets with less private information imposing net welfare costs on the economy when an insider s private information is valuable in making future investment decisions the net social benefit of inside trading can be positive the resulting increases in investment efficiency due to more informative prices is enough to compensate for the distortion induced by the inside trader when insiders receive private information more than once insiders may trade to reveal their private information at the beginning of their relationship with the firm this has two effects i more information is revealed in equilibrium and ii there is less chance than an uninformed agent will have to trade with the insider both these effects reduce the investment inefficiencies associated with insider trading as a consequence uninformed liquidity traders prefer to trade in a market with a long term insider this improvement in investment efficiency leads to a pareto improvement both the uninformed traders and the insider are made better off if the insider receives information more than once

insider trading legislation and corporate governance this paper analyzes the impact of insider trading legislation on corporate governance in a context where large dominant shareholders can monitor underperforming companies managers have an incentive to give early warnings about adverse developments to dominant shareholders this information is effectively a bribe to induce dominant shareholders to sell their stock and refrain from intervention if insider trading is unregulated dominant shareholders collude with management at the expense of small shareholders the optimal regime forces the company to disclose all material information to the market private contracting between companies and shareholders leads to optimal insider trading regulation only if initial shareholders can enter a binding commitment otherwise large shareholders and managers recontract at the expense of small share holders enforcement also matters european union legislation requires inside information to be precise such a narrow definition creates a grey zone where information is private but cannot be classified as inside information as a result the effectiveness of corporate governance and firm value are reduced regulation in the us that treats shareholders with a stake exceeding 10 as insiders is potentially harmful

restricting the means of exchange within organizations abstract this paper considers why firms often ban monetary exchange between their employees while encouraging these trades through other means such as through the reciprocation of favours or barter despite classical inefficiencies associated with non monetary exchange we illustrate two themes as to why non monetary trade may be preferred to allowing money first the use of non monetary trade may affect the allocation of rents in surplus enhancing ways as agents respond strategically to the existence of these rents second non monetary trade improves the ability of agents to impose sanctions on those who act dishonestly

nonmarket institutions for credit and risk sharing in low income countries the design credit and risk institutions in low income countries provides one of the most exciting testing grounds for theories of contracting with imperfect information and limited enforcement this paper reviews some of the recent literature with a special focus on nonmarket institutions that cope with risk and provide credit this literature attempts to bring together insights from economic theory especially information economics contract theory and mechanism design theory however it is also applied being motivated by the circumstance of the poor countries that their authors have visited and studied

the efficient market hypothesis and insider trading on the stock market we study the behavior of a large trader with private information about the mean of an asset with a risky return we argue that if the variability of the return is not too great typically the trader will find it desirable to ensure that the market price does not reveal his information that is that a pooling equilibrium arises such an equilibrium has the advantage of avoiding the incentive constraints that arise in separating equilibria where information can be inferred from prices thus the efficient market hypothesis may well fail if there is imperfect competition despite the uniformativeness of prices the other competitive traders are also better off in the pooling equilibrium than in any separating equilibrium again if one assumes limited variability

informal family insurance and the design of the welfare state we study unemployment benefit provision when the family also provides social insurance in the benchmark case more generous state transfers crowd out family risk sharing one for one an extension gives the state an advantage in enforcing transfers through taxes whereas families rely on self enforcement more generous state transfers lead to more than one for one reductions in intra family insurance so that total transfers to the unemployed fall as the state s generosity increases this does not imply that the optimal size of the welfare state is zero our results still hold when families are assumed to be better than the state at monitoring job search activities of unemployed

third party product review and firm marketing strategy product reviews by third parties are growing in popularity this paper examines when and how a manufacturing firm should adapt its marketing strategies to such reviews for example should a firm receiving an unfavorable review reduce its price or adjust its advertising should a winning product of a product review e g editor s choice boost its advertising expenditure to spread the good news how should firms strategic responses to product reviews differ across different types of product reviews description vs recommendation and different advertising media the reviewer s publication vs other media we develop a theory to address these issues and derive firms optimal responses to product reviews under different product market review media conditions we show that firms should chooseadvertising rather thanprice as a strategic variable in response to product reviews when enough consumers value horizontal product attributes surprisingly we find that using a review endorsedadvertising format i e advertisements containing third party award logos to broadcast its victory can hurt the winning product of a product review also it is not necessarily wise for the winning products to boostadvertising expenditures to spread the good news data from two industries printers and running shoes are used to illustrate some of our findings

the determination of unemployment benefits while much empirical research exists on labor market consequences of unemployment benefits there is remarkably little evidence on the forces determining benefits we present a simple model where workers desire insurance against unemployment risk and benefits increase the unemployment rate we then conduct one of the first empirical analyses of the determinants of the parameters of the benefit system using data for developed countries for 1971 89 controlling for year and country fixed effects and the government s political color we find evidence that the level of benefits falls when the unemployment rate is high this is consistent with wright s tax effect

advertising content when brand choice is a signal this article gives a formal rationale for image advertising and branding of homogeneous products that are consumed in public the idea is that consumers can use brand choice to coordinate behavior and send meaningful social signals the article distinguishes between variety signals and quality signals and analyzes the competitive implications copyright 1990 by the university of chicago

analyzing insider trading from the perspectives of utilitarian ethics and rights theory the common view is that insider trading is always unethical and illegal but such is not the case some forms of insider trading are legal furthermore applying ethical principles to insider trading causes one to conclude that it is also sometimes ethical this paper attempts to get past the hype the press reports and the political grandstanding to get to the truth of the matter the author applies two sets of ethical principles utilitarianism and rights theory in an attempt to determine when and in what circumstances insider trading is ethical the views of henry manne an early proponent of insider trading are critically examined as are the major arguments against insider trading is insider trading good for the company if it is used as a form of executive compensation which makes it possible to pay lower salaries than would otherwise be the case does insider trading cause the stock market to work more efficiently if insider trading does increase efficiency is that sufficient to call for its total legalization or are there other things to be considered several arguments against insider trading have been put forth over the last few decades but there are problems with all of them one of the main arguments is the fairness argument the problem with this argument is that different people have different definitions of unfairness a closely related argument is the level playing field argument which advocates wider dissemination of information so that it is less asymmetric one problem with the level playing field argument is that it is better applied to sporting competitions than to trading in information some economists argue that forcing the disclosure of nonpublic information can actually result in more harm than good and must necessarily involve the violation of property rights other arguments examined in this chapter include the fiduciary duty argument the problem of outside traders the misappropriation doctrine and the restrictions that insider trading laws place on freedom of speech and press the article concludes by setting forth some principles or guidelines to determine when insider trading should be punished and when it should not

how important is intra household risk sharing for savings and labor supply abstract while it is recognized that the family is a risk sharing institution little is known about the quantitative effects of this source of insurance on savings and labor supply in this paper we present a model where workers females and males are subject to idiosyncratic employment risk and where capital markets are incomplete a household is formed by a female and a male who decide on consumption savings and labor supplies in a calibrated version of our model we find that intra household risk sharing has its largest impact among wealth poor households while the wealth rich use mainly savings to smooth consumption across unemployment spells wealth poor households rely on spousal labor supply for instance for low wealth households average hours worked by wives of unemployed husbands are 8 higher than those worked by wives of employed husbands this response in wives hours makes up 9 of lost family income we also study consumption losses upon an unemployment spell precautionary savings and the crowding out effects of the public unemployment insurance program on the extent of risk sharing within the household

emergent extremism in a multi agent model of religious clubs i introduction religious extremism is as old as religion itself but the tendency to promote militancy and terrorism from within extremist religions appears to be much more common now than in times past juergensmeyer 2001 stern 2003 wiktorowicz 2005 1 today s terrorists routinely frame their objectives in religious terms and organize their activities within religious movements this shift is not due to increased militancy within religion as a whole not even within the stricter subset of religious groups commonly labeled sectarian or fundamentalist bromley and melton 2002 marty and appleby 1995 rather groups with militant objectives are increasingly leveraging the latent potential for violence within extremist religion krueger and maleckova 2003 and krueger 2007 have shown that contrary to popular hypotheses regarding the salience of poverty and education it is instead institutional conditions such as civil liberties that contribute to the origination of terrorists within a country religious extremism has been shown to be a potentially powerful input into the production of terrorism berman 2004 2 and the origination of terrorists has been empirically connected to civil liberties we seek to complete the triangle and connect religious extremism to social conditions in an extension of existing theory and test the predictions of the model in an empirical context with an eye toward civil liberties this paper extends previous models of religious clubs to better account for observed patterns of extremism across different settings and test policies most likely to reduce the appeal of extremism economists at first blush should have trouble explaining the survival of groups that demand large sacrifices from their members successful religious groups however routinely impose all sorts of apparently unproductive costs on their members iannaccone 1992 introduced a formal model of religious clubs within which apparently irrational sacrifice and stigma enhances the individual and collective utility his model demonstrated the feasibility of extremist groups but does less to explain the relative prevalence of extremism across time and place further the original model allows for only corner solutions and as such the viability of extreme groups is indistinguishable from the viability of the more moderate groups they must compete with for members in the religious marketplace in section ii we revisit analyze and extend the club model of religion we push the analysis of the original model exploring sacrifice substitutability of club and private goods and their relationships to member commitment and the viability of extremist groups in this preliminary analysis we illustrate not only the potential insights of the club theory of religion into the strength and viability of extremist groups but also the limitations inherent to the representative agent model we proceed by extending the model in a multi agent ma computational framework this framework permits us to analyze the distributions of agents and clubs that make up a religious economy the computational nature of the model is critical because it allows for sufficient heterogeneity of agents and clubs and given this heterogeneity agent decision making absent closed form solutions via nash equilibria extremists groups emerge as just one segment the high cost tail of a distribution of religious clubs that range across the full spectrum of potential group imposed sacrifice and stigma extremism is identifiable and comparable in the model because it exists within a full spectrum of clubs by varying the parameters of the model that control the distribution of secular wages across agents and the degree of substitutability between religious and secular commodities we can better explain where and when religious extremism is most popular its strength relative to more moderate groups and which economic policies reduce its prevalence

mixing behavior in cross country diffusion diffusion models represent one of the key successes in marketing science we understand a great deal about what influences and shapes within country diffusion patterns however we understand far less about what influences and shapes cross country or inter country diffusion patterns clearly for firms operating in a truly global environment understanding to what extent prior adoption in one country affects current and consequently future adoption in another country can be an important consideration further understanding how the pattern of interaction across countries impacts the diffusion process can have profound implications for product launch strategies for new durable products in this paper we address the extent to which prior adoption of a new product in one country affects adoption in other countries in particular we investigate the importance of the pattern of interaction what we call mixing across countries in the context of a new product diffusion model more specifically mixing refers to the pattern of communication within and across countries for example do italians communicate only with other italians or do they influence consumers in other countries understanding and empirically estimating how these mixing patterns across countries influence the subsequent diffusion process is the central research objective of this paper while previous research in marketing addressing cross country diffusion has assumed very specific forms of cross country interaction the present study develops and estimates a flexible form of mixing that allows for the simultaneous estimation of mixing patterns across multiple countries in particular we examine the effect of mixing behavior across populations on new product adoption viewing mixing as occurring across a continuum with segregation no mixing at one end and random mixing at the other intermediate forms of mixing lie along this continuum and are called bernoulli mixing in order to produce generalizable results we obtained sales data on four product categories in the european community ec nations vcrs from 1977 1990 microwave ovens 1975 1990 compact disc players 1984 1993 and home computers 1981 1991 for each product data were collected for 10 ec nations great britain germany france italy spain belgium denmark netherlands sweden and austria a diffusion model that incorporates cross country prior adoption cross country mixing patterns and individual country covariates was estimated simultaneously across the 10 countries for each of the four products on the basis of the empirical results we conclude that mixing behavior across segments is an important consideration in new product diffusion specifically the observed pattern of mixing and the strength of cross segment influences are important considerations in allocating the marketing mix during product introduction stages the practical implication of mixing behavior is that if one wishes to understand diffusion in belgium for example it is important to not only know the diffusion parameters in belgium but also those in other ec nations accordingly these results should be of interest to managers responsible for coordinating new product launches across countries and to researchers interested in investigating cross country diffusion issues as an example of the strategic implications of the results we note that under bernoulli mixing future country launches will benefit not only from prior adoption in countries with high overall contact rates but in particular from countries with high rates of contact with other countries although there is some variance across products in general germany france italy and spain are the most gregarious as measured by the rate of contact the results suggest that a strategy of first focusing on germany france italy and spain will maximize adoption in subsequent countries each of these countries tends to have a higher percentage of its contacts with individuals internal to its borders as well as with other countries this suggests that these countries would have relatively quick adoption internally while having a strong influence externally further for countries such as denmark netherlands austria and sweden a higher percentage of their contacts are derived from outside their borders thus seeding the diffusion process by introducing first in germany france italy and spain would benefit later adoption in countries such as denmark netherlands austria and sweden although the strength of the individual country influence varies from product to product this result is generally consistent across the four products

the sound of silence observational learning in the u s kidney market mere observation of others choices can be informative about product quality this paper develops an individual level dynamic model of observational learning and applies it to a novel data set from the u s kidney market where transplant candidates on a waiting list sequentially decide whether to accept a kidney offer we find strong evidence of observational learning patients draw negative quality inferences from earlier refusals in the queue thus becoming more inclined towards refusal themselves this self reinforcing chain of inferences leads to poor kidney utilization despite the continual shortage in kidney supply counterfactual policy simulations show that patients would have made more efficient use of kidneys had the concerns behind earlier refusals been shared this study yields a set of marketing implications in particular we show that observational learning and information sharing shape consumer choices in markedly different ways optimal marketing strategies should take into account how consumers learn from others

some remarks on leland s model of insider trading this paper shows that leland s 1992 results on the positive effects of insider trading on investment are not robust to the introduction of noise in the insider s information the paper then considers two variations of his model in which the insider is risk neutral to ensure robustness and the investment decision is prior to the placing of the stock in the market it is shown that if insider trading takes place in the primary market it has no effect on the level of investment whereas if it takes place in the secondary market it has a negative effect on investment ing debate insider trading moves the resolution of uncertainty forward and this may bring benefits better information for investment decisions as well as costs increased volatility of prices and hence higher risk premia to analyse these effects leland 1992 constructs a model with an endogen ous level of investment and he shows that when insider trading is permitted stock prices will be higher on average expected real investment will rise and markets will be less liquid and more volatile leland s model is however very special first of all he assumes that the risk averse insider learns exactly the future return of the risky asset in this paper i analyse the robustness of leland s results to the introduction of some noise in the insider s information i show that given the assumptions of his model an arbitrarily small amount of noise is sufficient to make negligible all the effects of insider trading the source of this lack of robustness lies in the assumption that because of risk aversion the insider s trade is always negligible except in the limit case where holding the asset entails no risk to ensure robustness to the intro duction of noise in the insider s information i then consider a model with a risk neutral insider however for this model insider trading does not have any effect on the average price of the risky asset and hence no effect on the average level of investment another feature of leland s model is the fact that the only supplier of the risky asset is assumed to be a price taker this seems a fairly implausible assumption so i propose an alternative model with a risk neutral insider in which the investment decision is prior to the placing of the asset in the market and which allows the supplier to have market power the equilibrium of this model can be easily derived from leland s analysis and although we get the same results for the volatility of the price and the liquidity of the market now insider trading has no effect on the level of investment the result however depends crucially on the assumption that the supplier of the asset is risk neu tral under risk aversion the increase in price volatility would imply a negative

the strategic impact of references in business markets we investigate a business to business context and ask when and why a firm should announce a reference program that commits the firm to facilitating the flow of information about the efficacy of its products from early adopters to potential late adopters we model a monopolist manufacturer with a new innovation that can be sold to two potential customers we demonstrate here two benefits of a reference program that relate not to an increase in later adopters willingness to pay but to an increase in the willingness to pay of the early adopters themselves the impact on the early adopters willingness to pay arises in two ways as a result of their observation of the firm s commitment to information transmission first in a model of symmetric uncertainty we show that the announcement of a reference program facilitates dynamic pricing by the manufacturer in the sense that it allows the firm to provide temporary exclusive use of the technology to one of the customers this creates more value which the manufacturer can extract via a higher price in this way a reference program can serve as a partial substitute for an exclusive use contract in a model with asymmetric information we demonstrate that under certain conditions the firm is able to use the reference program as a signal again to the early adopting customer that its technology is of high quality however such a signal requires significant discounts to early adopters to ensure separation as a result a pooling equilibrium dominates in which the manufacturer fosters references regardless of its quality finally by allowing the firms private information to be stochastic we show that separation may be a dominant outcome

generic existence of completely revealing equilibria for economies with uncertainty when prices convey information conditions which imply the existence of strict rational expectations equilibria for most static pure exchange economies where prices convey information about the state of the world are analyzed information is aggregated and transmitted by prices because agents have different initial information and maximize the conditional expectation of state dependent utility functions major results state that if with probability one agents characteristics do not vary too much as the state of the world varies then generically there exist equilibrium price functions which reveal all initial information more precisely if the support of the image measure is contained in a compact c1 manifold satisfying some technical conditions which is of sufficiently low dimension relative to the number of commodities then existence of completely revealing equilibria is generic any economy satisfying these assumptions can be approximated by a sequence of economies which also obey these assumptions and have completely revealing equilibrium price functions slight perturbations do not destroy the existence property

the role of information and social interactions in retirement plan decisions evidence from a randomized experiment this paper analyzes a randomized experiment to shed light on the role of information and social interactions in employees decisions to enroll in a tax deferred account tda retirement plan within a large university the experiment encouraged a random sample of employees in a subset of departments to attend a benee ts information fair organized by the university by promising a monetary reward for attendance the experiment multiplied by more than e ve the attendance rate of these treated individuals relative to controls and tripled that of untreated individuals within departments where some individuals were treated tda enrollment e ve and eleven months after the fair was signie cantly higher in departments where some individuals were treated than in departments where nobody was treated however the effect on tda enrollment is almost as large for individuals in treated departments who did not receive the encouragement as for those who did we provide three interpretations differential treatment effects social network effects and motivational reward effects to account for these results

endogenous adverse selection and unemployment insurance in this paper we consider how the presence of private information may explain the failure of the private sector to provide unemployment insurance in particular we show how the interaction of private information regarding employees preferences for work with the unobservable level of effort exerted on the job may explain the absence of private unemployment insurance we also reflect on the implications of our findings for the role of the public sector in providing unemployment insurance

consumption smoothing in island economies can public insurance reduce welfare abstract in this paper we study the effects of certain types of public compulsory insurance arrangements for aggregate shocks on private allocations in environments with limited commitment we show that this type of insurance can improve the wellbeing of private situations but it can also deteriorate it we also describe how different characteristics of the environment affect the role of public insurance using data on the mexican progresa program we document the impact that some government programs have in crowding out private transfers

ex ante payments in self enforcing risk sharing contracts abstract we analyze a long term risk sharing contract between two risk averse agents facing self enforcing constraints we enlarge the contracting space to allow for an ex ante transfer before the state of nature is realized and we characterize the optimal ex ante and ex post payments we show that optimal ex ante payments are inversely related to the non stationary expected surplus with i i d shocks the dynamics of the optimal contract exhibit experience rating even though there is no private information or learning taking place finally we assess numerically the value of introducing the ex ante payment as well as compare the dynamics of consumption with and without this payment journal of economic literature classification numbers c61 c63 e21 g22 d90

does public welfare crowd out informal safety nets ethnographic evidence from rural latin america abstract the researchers compare ethnographic data from two neighboring countries suriname and french guiana to investigate whether public welfare systems displace informal risk sharing arrangements the results suggest that the informal safety nets of poor rural households are deficient when shocks are extreme irreversible cumulative and co variate public welfare can reduce poverty by strengthening informal insurance systems distributing cash enabling new risk management strategies and promoting human capital development it remains a challenge for policy makers to implement welfare systems that cover society members with the lowest levels of human and social capital and that minimize adverse consequences of economic change

insider trading in a rational expectations economy it is often argued that efficiency considerations require society to freely permit insider trading in this article an opposing efficiency argument is formalized the model incorporates an investment stage followed by a trading stage if outsiders expect insiders to take advantage of them in trading outsiders will reduce their investment the insiders loss from this diminished investor confidence may more than offset their trading gains consequently a prohibition on insider trading may effect a pareto improvement insiders are made better off if they can precommit not to trade on their privileged information govemment regulation accomplishes exactly this jel 022 026 313 the traditional rationale articulated for insider trading regulation and other securities law is that such rules promote confidence in markets indeed president franklin d roosevelt justified the first major u s securities legislation by saying it should give impetus to honest dealing in securities and thereby bring back public confidence similar language is still invoked half a century later in connection with enforcement efforts against insider trading and in proposals for tightened stock

price and advertising signals of product quality we present a signaling model based on ideas of phillip nelson in which both the introductory price and the level of directly uninformative advertising or other dissipative marketing expenditures are choice variables and may be used as signals for the initially unobservable quality of a newly introduced experience good repeat purchases play a crucial role in our model a second focus of the paper is on illustrating an approach to refining the set of equilibria in signalling games with multiple potential signals

the redistributive roles of unemployment insurance and the dynamics of voting abstract public unemployment insurance is analyzed as the majority voting equilibrium policy of a dynamic stochastic economy abstracting from incentive effects we focus on redistribution some results are because of the distribution of heterogeneous employment opportunities public insurance may be democratically chosen even if complete private markets exist and because of the dynamics even when agents are intrinsically homogeneous the equilibrium benefit level or duration benefit schedule deviates from what has been described as optimal in the literature the effects of differences in the average frequency or duration of unemployment on equilibrium taxes and benefits are investigated with some unanticipated results

motives for private income transfers private income transfers are becoming increasingly recognized as a key aspect of the u s economy the majority of private income transfers occur inter vivos i e between living persons but very little is known about this type of transfer behavior this paper tests alternative hypotheses concerning motivation for inter vivos transfers two motives are considered altruism and exchange evidence presented here casts doubt on the altruistic model of transfer behavior observed patterns for inter vivos transfers are more consistent with exchange related motives this finding has important implications for the effects of public transfer programs on the distribution of economic well being

do demand curves for stocks slope down since september 1976 stocks newly included into the standard and poor s 500 index have earned a significant positive abnormal return at the announcement of the inclusion this return does not disappear for at least ten days after the inclusion the returns are positively related to measures of buying by index funds consistent with the hypothesis that demand curves for stocks slope down the returns are not related to s p s bond ratings which is inconsistent with a plausible version of the hypothesis that inclusion is a certification of the quality of the stock

market research and innovation strategy in a duopoly we model a duopoly in which ex ante identical firms must decide where to direct their innovation efforts the firms face market uncertainty about consumers preferences for innovation on two product attributes and technology uncertainty about the success of their research and development r d investments firms can conduct costly market research before setting r d strategy we find that the value of market information to a firm depends on whether its rival is expected to obtain this information in equilibrium consequently one firm may forgo market research even though its rival conducts such research and learns the true state of demand we examine both vertical and horizontal demand structures with vertical preferences firms are a priori uncertain about which attribute all consumers will value more in this case a firm that conducts market research always attempts innovation on the attribute it discovers that consumers prefer and expends more on r d than a rival that has not conducted market research with horizontal preferences distinct segments exist each caring about innovation on only one attribute and firms are a priori uncertain how many consumers each segment contains in this case a firm that conducts market research may follow a niche strategy and attempt innovation to serve the smaller segment to avoid intense price competition for the larger segment a firm that conducts market research may therefore invest less in r d and earn lower postlaunch profits than a rival that has forgone such research

corruption and local democratization in indonesia the role of islamic parties indonesia has a tradition of corruption among local officials who harass and collect bribes from firms this paper examines whether corruption is affected by local democratization and by the party composition of local assemblies democratization occurred in 1999 and decentralization in 2001 we have firm level data for 2001 and 2004 the 2001 data benchmark corruption at the time of decentralization we find that corruption declines between 2001 and 2004 overall but much less so in districts with more secular party as opposed to islamic party representatives in district assemblies for a larger sample of districts correspondingly we find that corruption in 2004 is more in districts which voted more in favor of secular party representatives in the first elections in 1999 we argue that the effects seem to be causal over above any effects of changing religiosity and economic circumstances across districts

implicit contracts incentive compatibility and involuntary unemployment this paper considers the enforceability of employment contracts when employees performance cannot be verified in court so that piece rate contracts are not legally enforceable part i shows that there exists a variety of self enforcing implicit contracts modelled as perfect equilibria in a repeated game and characterizes all the wage and performance outcomes that can be implemented implementation requires a strictly positive surplus from employment the form of the contract depending on how this surplus is divided between firm and employee piece rate contracts and contracts with an informally agreed bonus can be made self enforcing but the use of severance pay and bonding does not extend the set of implementable allocations the resulting contracts resemble actual labor contracts more than do the contracts in standard principal agent models part ii analyses market equilibrium with these contracts also modelled as perfect equilibria in a repeated game and shows that many such equilibria exist unfilled vacancies and unemployed workers can co exist despite the existence of contracts that are potentially mutually beneficial for those jobs that are filled any division of the potential surplus is possible so that the market can have at the same time involuntary unemployment and vacancies that are unfilled despite filled jobs earning positive profits as a criterion for selecting equilibria a notion of renegotiation proofness is applied then either all workers are employed or all jobs filled but any division of the potential surplus is still possible the paper explores what further restrictions on beliefs give rise to a walrasian outcome in which all the potential surplus goes to the short side of the market and to an efficiency wage type outcome in which the potential surplus goes to the long side

using privileged information to manipulate markets insiders gurus and credibility access to private information is shown to generate both the incentives and the ability to manipulate asset markets through strategically distorted announcements the fact that privileged information is noisy interferes with the public s attempts to learn whether such announcements are honest it allows opportunistic individuals to manipulate prices repeatedly without ever being fully found out this leads us to extend sobel s 1985 model of strategic communication to the case of noisy private signals our results show that when truthfulness is not easily verifiable restrictions on trading by insiders may be needed to preserve the integrity of information embodied in prices

partially revealing rational expectations equilibrium in a competitive economy abstract a class of pure exchange economies is considered in which some agents are informed of private information and others are uninformed existence of a partially revealing rational expectations equilibrium ree is proved without restricting attention to particular functional forms for utility functions and probability distributions without introducing noise into the model and without departing from the standard definition of ree the equilibrium is robust in the sense that if the primitives of the economy are slightly perturbed the economy continues to have a qualitatively similar ree with somewhat stronger assumptions placed on the economy the equilibrium is also the unique measurable ree

self enforcing wage contracts we examine long term wage contracts between a risk neutral firm and a risk averse worker when both can costlessly renege and buy or sell labour at a random spot market wage a self enforcing contract is one in which neither party ever has an incentive to renege in the optimum self enforcing contract wages are sticky they are less variable than spot market wages and positively serially correlated they are updated by a simple rule around each spot wage is a time invariant interval and the contract wage changes each period by the smallest amount necessary to bring it into the current interval