speculative attacks unique equilibrium and transparency abstract models with multiple equilibria are a popular way to explain currency attacks morris and shin 1998 have shown that in the context of those models unique equilibria may prevail once noisy private information is introduced in this paper we apply the method of morris and shin to a broader class of probability distributions and show using the technique of iterated elimination of dominated strategies that their results continue to hold even if we allow for sunspots and individual uncertainty about strategic behavior of other agents we provide a clear exposition of the logic of this model and we analyze the impact of transparency on the probability of a speculative attack for the case of uniform distribution of noisy signals we show that increased transparency of government policy reduces the likelihood of attacks

bank runs liquidity costs and investment distortions abstract in this paper we extend the diamond and dybvig 1983 model of intermediation to study further the conditions under which bank runs can occur and to consider how private parties might adjust to the existence of bank run equilibria we provide weaker necessary conditions for runs we then characterize how banks respond to the possibility of runs in their design of deposit contracts and investment decisions banks might choose to offer contracts that prevent runs but under some conditions the second best contracts will involve accepting some risk of runs in order to achieve higher expected returns from their investments

the pricing of durable exhaustible resources partial or total durability characterizes a large class of exhaustible resources hotelling s r percent rule will apply to a durable resource produced in a competitive market but will not apply if the resource is produced in a monopolistic market however the r percent rule does not mean that price is steadily rising it is shown that in general the competitive market price will fall initially as the stock in circulation increases and later will rise as the stock decreases and eventually depreciates toward zero after production ceases accounting for durability may thus help explain the u shaped long term price profiles observed for many resources 11 references 3 figures

banking panics information and rational expectations equilibrium this paper shows that bank runs can be modeled as an equilibrium phenomenon we demonstrate that some aspects of the intuitive story that bank runs start with fears of insolvency of banks can be rigorously modeled if individuals observe long lines at the bank they correctly infer that there is a possibility that the bank is about to fail and precipitate a bank run however bank runs occur even when no one has any adverse information extra market constraints such as suspension of convertibility can prevent bank runs and result in superior allocations banking panics were a recurrent phenomenon in the united states until the 1930s they have re emerged as a source of public concern and much theoretical research recently in this paper we provide an information theoretic rationale for bank runs the traditional story is that contagion is an important aspect of bank runs the idea seems to be that when the general public observes large withdrawals from the banking system fears of insolvency grow resulting in even larger withdrawals of deposits in our model some individuals withdraw because they get information that future returns are likely to be low uninformed individuals observing this also have an incentive to liquidate their investments in addition some individuals need to withdraw deposits for other than informationally based reasons thus if the random realization of such a group of individuals is unusually large then the uninformed individuals will be misled and will precipitate a run on the bank the technology is such that a large volume of withdrawals involves liquidation costs consequently runs on the bank do impose social costs a mechanism that may reduce these costs in our model is to suspend convertibility if withdrawals are high however those individuals who need to withdraw their assets for liquidity reasons are worse off ex post our model provides a rationalization for restrictions in demand deposits that were widespread prior to 1929 friedman and schwartz 7 suggest that restrictions of payments ensured

understanding bank runs the importance of depositor bank relationships and networks we use a unique new database to examine micro depositor level data for a bank that faced a run we use minute by minute depositor withdrawal data to understand the effectiveness of deposit insurance the role of social networks and the importance of bank depositor relationships in influencing depositor propensity to run we employ methods from the epidemiology literature which examine how diseases spread to estimate transmission probabilities of depositors running and the significant underlying factors we find that deposit insurance is only partially effective in preventing bank runs further our results suggest that social network effects are important but are mitigated by other factors in particular the length and depth of the bank depositor relationship depositors with longer relationships and those who have availed of loans from a bank are less likely to run during a crisis suggesting that cross selling acts not just as a revenue generator but also as a complementary insurance mechanism for the bank finally we find there are long term effects of a solvent bank run in that depositors who run do not return back to the bank our results help understand the underlying dynamics of bank runs and hold important policy implications

information and the persistence of private order contract enforcement institutions an experimental analysis abstract we study an experimental market in which some sellers are prone to moral hazard and in which a private order contract enforcement institution exists that can mediate trade and prevent sellers from reneging on their contractual obligations using the institution to resolve the moral hazard problem is costly we demonstrate that in this market the utilization of the private order contract enforcement institution may make public and private market signals uninformative and inhibit learning we study whether this potential information externality can limit adaptation away from the private order institution when it is efficient to do so consistent with theory we find inefficient persistence when the institution is used but by contrast efficient adaptation in other situations providing information to individuals who are using the private order institution allows them to partially adapt

on avoiding bank runs abstract can bank runs be avoided and should they be avoided i analyze a banking environment where bank runs can occur as a result of negative signals about the bank s investments in this environment banks can make sure that runs do not occur by designing the deposit contract appropriately i show that there are conditions under which it is profit maximizing for the bank to avoid runs and others under which occasional runs are part of optimal bank behavior i also compare the banking arrangement to an arrangement based on trading in equity

a limited sample benchmark approach to assess and improve the performance of risk equalization models abstract a new method is proposed to assess and improve the performance of risk equalization models in competitive markets for individual health insurance where compensation is intended for variation in observed expenditures due to so called s ubsidy type risk factors but not for variation due to other so called n on subsidy type risk factors given the availability of a rich subsample of individuals for which normative expenditures ynorm can be accurately determined we make two contributions a any risk equalization scheme applied to the entire population yref should be evaluated through its performance in the subsample by comparing yref with ynorm not by comparing yref with observed expenditures y in the entire population as commonly done b conventional risk equalization schemes can be improved by the subsample regression of ynorm rather than y on the risk adjusters that are observable in the entire population this new method is illustrated by an application to the 2004 dutch risk equalization model

risk adjustment and prevention widespread integration of market based incentives into healthcare systems calls for and has elicited increasing adoption of risk adjustment by deterring selection risk adjustment helps to assure fair and efficient payments among health insurers or capitated provider groups however since conventional risk adjustment allocates funds among regions or insurers according to current population health status it does not reward indeed it penalizes preventive efforts that improve population health this prevention penalty of risk adjustment represents a hidden cost of unclear magnitude undermining provider incentives for health promotion we develop a theoretical model of selection and prevention demonstrating this problem with conventional risk adjustment and suggesting a simple alternative risk adjustment should be linked to pay for performance for prevention l integration generalisee d incitatifs mercantiles dans les systemes de soins de sante appelle et a engendre l adoption croissante d ajustements au risque en decourageant la selection l ajustement au risque aide a assurer des paiements justes et equitables entre les assureurs ou les groupes de fournisseurs finances par capitation cependant comme les ajustements conventionnels au risque allouent des fonds entre les regions ou les assureurs selon le statut sanitaire present de la population ils ne recompensent pas et meme penalisent les efforts de prevention qui ameliorent la sante des populations cette penalisation de la prevention dans les ajustements au risque represente un cout cache d une magnitude mal etablie qui mine l incitation des fournisseurs a s occuper de promotion de la sante on developpe un modele theorique de selection et de prevention mettant en lumiere ce probleme dans l utilisation de l ajustement au risque conventionnel et on suggere une solution de rechange ou l ajustement au risque est reliea une remuneration a la performance pour la prevention

financial contagion in the laboratory does network structure matter we explore the role of interbank network structure and premature liquidation costs for the likelihood of financial contagions in a laboratory experiment we consider complete versus incomplete networks of banks linked together by interbank deposits and we further vary premature liquidation costs subjects play the role of depositors deciding whether or not to withdraw funds from their interconnected bank we find that when liquidation costs are high a complete network structure is significantly less vulnerable to financial contagions than an incomplete network structure however when liquidation costs are low network structure is less important for the frequency of financial contagions

common property resources storage facilities and ownership structures a cournot model of the oil market during the last decade economists have tried hard to convince meadows and his followers that market forces do not tend to exhaust our natural resources too rapidly as compared with the requirements of an intertemporal pareto optimum it is well known now that under well defined property rights and correct price expectations a competitive extraction industry brings about a pareto optimal depletion path and it has been shown that oligopolistic and monopolistic market structures may even produce a bias towards conservation 1 it is still an unresolved issue however which extraction path will result if property rights are imperfectly defined following the pioneering work of gordon 1954 there has been a large body of literature demonstrating that in the extreme case of free entry and myopic profit maximization there are strong reasons for excessive extraction 2 but this literature hardly yields reliable conclusions for the perhaps more realistic case where firms derive their behaviour from intertemporal optimization and where there is a common ownership but limited access to the resource the basic intuition behind the common pool problem is that the individual agent chooses an extraction policy other than the one he would choose under well defined property rights since he is afraid that part of the resource he leaves underground will be extracted and sold by others 3 despite the simplicity of this intuition there does not seem to be any publication that analyses it within an intertemporal equilibrium model with rational and far sighted agents this is the motivation for the present approach the approach studies the common pool problem in the context of an oligopolistic world market for oil it posits a given number of identical firms extracting oil from holdings between some of which there is mutual seepage the firms sell the extracted oil in the same market or they store it in privately owned seepage proof tanks each firm derives its behaviour from intertemporal optimization under perfect foresight of the time paths of the model variables but cournotesque conjectures about the reactions of its competitors except for the assumption of storage facilities this specification is closely related to models previously studied by khalatbari 1977 and kemp and long 1980 essay 10 4 the two models are very similar but they yield strikingly different conclusions while kemp and long find that the extraction path chosen by the firms is pareto optimal i e that the price of the resource rises at a rate given by the market rate of interest khalatbari contends that there is over extraction kemp and long convincingly demonstrate that khalatbari s model suffers from an inconsistency in the way the individual firm expects its rivals to respond to its own actions and they argue that this inconsistency is the reason for the divergence in results thus the casual reader gets the

unique equilibrium in a model of self fulfilling currency attacks comment in a recent issue of this journal stephen morris and hyun song shin 1998a prove the uniqueness of an equilibrium in a model of self fulfilling currency attacks when speculators face uncertainty in their signals about macroeconomic fundamentals in theorem 2 of their paper morris and shin characterize the equilibrium as uncertainty approaches zero they claim that the threshold of the fundamental state up to which a currency attack will occur with probability one is independent of the critical mass of capital needed for an attack to be successful hence direct capital controls are less effective when speculators have fairly precise information about fundamentals yet their theorem 2 holds only for a special case this comment gives the correct generalization and proves that for small uncertainty currency crises depend on the critical mass of capital needed for success thus direct capital controls are effective even when fundamentals are fairly transparent to all market participants the reduced game structure is given by the following assumptions fundamentals of the economy are characterized by some parameter u unknown to agents there is a continuum of agents receiving independently and identically distributed i i d signals x about the fundamentals each agent must decide whether or not to attack the currency which is associated with transaction costs t 0 if a proportion a u of all traders attacks the currency the attack is successful and each attacking agent obtains a reward r u 5 e 2 f u a and r are continuous there is a state u with a u 5 0 for all u u a is strictly increasing above u and a u 1 for all u r is strictly decreasing and there is a state u u with r u 5 t u is uniformly distributed over an interval say 0 1 given u signals have a uniform distribution in u 2 u 1 critical levels u and u must be at least 2 away from the margins of the interval 0 1 in section ii of their paper morris and shin show that a unique equilibrium switching point x and a threshold u exist such that an agent attacks does not attack the currency if her signal x is smaller larger than x and that a successful speculative attack occurs with probability one zero if state u is below above u in section iii theorem 2 states that in the limit as tends to zero u is given by the unique solution to the equation f u 5 e 2 2t p 594 as stated this theorem holds only for the special case where a u 5 1 2 it should therefore be generalized as follows

banking as the provision of liquidity this article represents a model economy in which demand deposits represent the optimal financial intermediation because these demand deposits are backed in part by an illiquid asset the in termediary bank is subject to panics in which each agent ration ally decides to withdraw his deposits making all worse off banks ca n prevent panics only through a distortion of the optimal contract t he government can prevent panics without this distortion by guarantee ing the return from deposits the moral hazard introduced by this dep osit insurance induces the government to regulate the intermediary s portfolio and returns copyright 1988 by the university of chicago

liquidity regulation banking history and financial fragility an experimental examination abstract we report an experiment conducted to evaluate interactions between liquidity requirements and depositors experiences with the banking system treatments consist of combinations of required liquidity levels and weak or strong background conditions intended to induce stable histories of play with few bank runs or unstable histories of play where bank runs are common experimental results suggest that both increased liquidity levels and a stable history of play improve the incidence of coordination on the pareto preferred no run outcome nevertheless even with an unstable history non degenerate no run outcomes occur quite reliably with high liquidity requirements

forward induction in the battle of the sexes games this paper provides experimental evidence on forward induction as a refinement criterion in the basic extensive form one of the two players chooses to play a battle of the sexes game or to receive a certain payoff according to forward induction choosing to play the game is a signal about intended action though the presence of the outside option changes play we find only limited support for the forward induction hypothesis the effects of the outside option also reflect the creation of a focal point through the asymmetry created by offering the outside option to one of the two players jel c72

the interaction of direct and indirect risk selection abstract this paper analyzes the interaction of direct and indirect risk selection in health insurance markets it is shown that direct risk selection using measures unrelated to the benefit package like selective advertising or losing applications of high risk individuals nevertheless has an influence on the distortions of the benefit package caused by indirect risk selection direct risk selection drs may either increase or decrease these distortions depending on the type of equilibrium pooling or separating the type of drs positive or negative and the type of cost for drs individual specific or not regulators who succeed in reducing drs by e g banning excessive advertising or implementing fines for losing applications may therefore unintendedly mitigate or exacerbate the distortions of the benefit package caused by indirect risk selection it is shown that the interaction of direct and indirect risk selection also alters the formula for optimal risk adjustment

imperfect risk adjustment risk preferences and sorting in competitive health insurance markets abstract i develop a model of insurer price setting and consumer welfare under risk adjustment a policy commonly used to combat inefficient sorting due to adverse selection in health insurance markets i use the model to illustrate graphically that risk adjustment causes health plan prices to be based on costs not predicted by the risk adjustment model residual costs rather than total costs either weakening or exacerbating selection problems depending on the correlation between demand and costs predicted by the risk adjustment model i then use a structural model to estimate the welfare consequences of risk adjustment finding a welfare gain of over 600 per person year

evolution coordination and banking panics abstract i study equilibrium selection by an evolutionary process in an environment with multiple equilibria one of which involves a banking panic the analysis is built on a repeated version of the diamond dybvig 1983 model the optimal equilibrium is uniquely selected if it is also risk dominant when there are multiple banks the probability of observing a panic increases as the size of the banks decreases local interaction generates contagion effects that allow a bank run to spread first among banks in the same geographic location and then throughout the population

unique equilibrium in a model of self fulfilling currency attacks even though self fulfilling currency attacks lead to multiple equilibria when fundamentals are common knowledge we demonstrate the uniqueness of equilibrium when speculators face a small amount of noise in their signals about the fundamentals this unique equilibrium depends not only on the fundamentals but also on financial variables such as the quantity of hot money in circulation and the costs of speculative trading in contrast to multiple equilibrium models our model allows analysis of policy proposals directed at curtailing currency attacks

consumer perception of deposit insurance little awareness limited effectiveness the empirical findings on bank runs and market discipline are at odds with the theoretical predictions from the literature at least in emerging markets using unique survey data from the netherlands we explore two possible explanations deposit holders may have limited knowledge of deposit insurance di schemes or they may not fully trust these schemes to be executed faithfully we find that knowledge on the eligibility for di is limited particularly when it concerns minor banks nevertheless households with more deposits have better knowledge of the di scheme and show higher levels of trust in addition deposit holders generally expect an associated payback time that well exceeds the time it has taken to pay back depositors in the past moreover consumers believe repayment is more likely and faster for large systemic banks these results confirm that both households awareness of the coverage and trust in the operations of the di scheme are suboptimal

the pricing of durable exhaustible resources comment in its simplest form hotelling s 1931 r percent rule states that in a competitive market with no extraction costs the price of an exhaustible resource will grow at the rate of interest for instance if price grows at a rate slower than the rate of interest it is in the interest of each firm to sell its entire stock immediately the hypothesized price path is obviously not an equilibrium even if there are extraction costs and firms are not identical it remains true that price net of marginal cost rises at the rate of interest the proposition generalizes to monopolized resources along the equilibrium path of extraction net marginal revenue grows at the rate of interest in a recent article in this journal levhari and pindyck 1981 henceforth l p show the r percent rule extends to durable exhaustible resources in a competitive market but they conclude that it does not hold in a monopoly market this is a surprising result following the hotelling logic should it not be possible for the monopolist to rearrange production from low net marginal revenue dates to high net marginal revenue dates and raise its present value the primary purpose of this comment is to show that hotelling s rule does in fact hold this is shown in section ii our result is compared with that of l p in section iii the conflict is shown to arise from a disagreement over the relevant marginal revenue in continuous time increasing the flow of production of a durable good at a particular point in time has no effect on the sales price at that or any other point in time hence the rate of change in the flow of revenue at that particular point in time is the sales price this is the definition of marginal revenue l p use however durables are different from nondurables in that a perturbation in the production trajectory over some length of time will affect the entire sales price trajectory in choosing its

cost minimizing risk adjustment conventional risk adjustment which sets capitation payments equal to the average cost of individuals with similar observable characteristics is not optimal if health plans can use private information to select low cost enrollees cost minimizing risk adjustment minimizes the sum of capitated hmo premiums plus ffs costs by balancing the gains from hmo cost efficiency against the overpayments that result from hmo selection estimations using privately insured data suggest that cost minimizing risk adjusted premiums reduce total sponsor costs as much as 25 6 below conventional risk adjustment premiums

an incentive approach to banking regulation we examine the optimal design of a risk adjusted deposit insurance scheme when the regulator has less information than the bank about the inherent risk of the bank s assets adverse selection and when the regulator is unable to monitor the extent to which bank resources are being directed away from normal operations toward activities that lower asset quality moral hazard under a socially optimal insurance scheme 1 asset quality is below the first best level 2 higher quality banks have larger asset bases and face lower capital adequacy requirements than lower quality banks and 3 the probability of failure is equated across banks perihaps t he most troubling aspect of the current deposit insurance system is the distortions caused by the pervasive use of an insurance premium that is independent of risk the undesirable incentives that result when such a system is employed in a world with imperfect information have long been recognized in the literature of particular concern is the incentive banks have to increase the risk of their portfolio in order to maximize the value of the deposit insurance provided in some respects this problem is similar to the incentives generated by corporate debt however the solution to this problem may be different in a banking context because the creditors include the deposit insurer who has the power to regulate the banks conceivably regulation may be able to mitigate the informational problem at hand in this paper we examine some of the tradeoffs that arise in the design of a regulatory system for banks

are currency crises self fulfilling abstract this paper studies the respective roles of the fundamentals and self fulfilling speculation in currency crises we first present a model of a fixed exchange rate system in which self fulfilling speculation can arise following a bifurcation in the fundamentals we then estimate the model in the case of the 1992 3 crisis of the french franc and find some evidence that self fulfilling speculation was at work

cartel stability in an exhaustible resource model a simple oligopolistic common pool exhaustible resource game is considered by analysing punishment strategies including optimal punishments it is possible to determine which cartel agreements are implementable in a non cooperative play of the game joint profit maximizing allocations are sustainable for sufficiently low discounting but in general it is shown that no folk theorem exists for this model in particular for sufficiently high elasticities of demand it is shown that optimal punishments are not sufficiently severe to enforce most stationary symmetric extraction paths thus confirming the hypothesis that sufficient market power is needed for a cartel to be stable a simple common property exhaustible resource model in a discrete time infinite horizon framework will be considered by looking at punishments levelled against firms that deviate from an implicitly agreed extraction path it is possible to examine the extent to which different allocations can be supported as non cooperative equilibria we shall pay particular attention to the question of whether punishments can be severe enough to sustain implicit agreements that maximize joint profits and to the idea pindyck 1979 that cartel stability depends crucially upon market power this non cooperative approach to the question of cartel stability has been used by porter 1983 in a repeated oligopoly model with imperfect information see also green and porter 1984 while we assume perfect observability here the model is compli cated by the existence of a state variable in the form of the resource stock moreover we shall apply the idea of optimal punishments in this dynamic model abreu et al 1986 1990 have looked at general properties of the equilibrium set in the green porter model what we find is that by considering a more general strategy space than that conventionally studied cooperative extraction rates are sustainable in equilibrium for low enough discount rates in contrast to the over extraction results often obtained moreover in this model the predictions concerning the range of possible sustainable equilibria as the discount rate approaches zero are sharp while the cooperative solution belongs to the set of equilibria for low discount rates constant symmetric extraction paths below the maximum possible rate fail to be sustainable in the limit if the elasticity of demand is sufficiently high thus for low discount rates only extraction rates close to the cooperative rate are sustainable together with disagreement equilibria which involve very high extraction rates these results are in sharp contrast to those obtained from repeated games where in the limit the range of equilibria is very large the difference is explained by the existence of a state variable in the form of a declining stock of the resource these results are also in contrast to what can happen in our model when the demand elasticity is lower all constant symmetric extraction paths may be sustainable for low enough

distinguishing panics and information based bank runs welfare and policy implications in this paper we contrast panics and information based bank runs in an effort to provide a robust and empirically plausible model of how bank runs are triggered the model of information based runs is characterized by two sided asymmetric information the bank cannot observe the true liquidity needs of the depositors while depositors are asymmetrically informed about bank asset quality we also examine the relative degrees of risk sharing provided by bank deposit contracts and traded equity contracts we show that the choice of deposit or equity depends on the attributes of and information about the underlying investment returns

much ado about two reconsidering retransformation and the two part model in health econometrics in health economics applications involving outcomes y and covariates x it is often the case that the central inferential problems of interest involve e y x and its associated partial effects or elasticities many such outcomes have two fundamental statistical properties y 0 and the outcome y 0 is observed with sufficient frequency that the zeros cannot be ignored econometrically this paper 1 describes circumstances where the standard two part model with homoskedastic retransformation will fail to provide consistent inferences about important policy parameters and 2 demonstrates some alternative approaches that are likely to prove helpful in applications

adverse selection and regulation in health insurance markets abstract in this paper we look at various ways to regulate the health insurance market and ask whether they provide an answer to the problem of adverse selection to avoid inefficiency government policy must either effectuate some cross subsidization of insurance policies within the state sector or grant private insurance firms an exclusive right to serve certain groups of the population recent reforms in the netherlands and germany and president clinton s proposals for the us could be adapted to fulfil these requirements efficiency cannot be achieved on the other hand if the regulator tries to prescribe cross subsidization within the private sector

cream skimming incentives for efficiency and payment system reform proposals of health care systems in several countries have advocated variations of a risk adjustment capitation system these proposals face a serious objection incentives to risk selection are prevalent in the system by now considerable literature has been devoted to finding ways of mitigating if not eliminating this problem while at the same time preserving incentives to efficiency we contribute to this debate presenting a transfer system that under some circumstances attains both provider efficiency and no risk selection the transfer system extends typical linear payment systems it can be interpreted as a fixed transfer in the beginning of the period plus an ex post fund at the end of the period the novelty rests in the way contributions to this fund are defined

deposit insurance regulation and moral hazard in the thrift industry evidence from the 1930 s this paper compares risk taking of insured and uninsured thrifts operating under strict and less strict regulatory regimes during the 1930 s analysis of balance sheet data indicates that while newly insured thrifts undertook less risk than their uninsured counterparts possibly because of screening by deposit insurance authorities moral hazard emerged gradually insured institutions operating under relatively permissive regulatory regimes were more prone to undertake risky lending activities than their more tightly regulated counterparts possibly because of screening by deposit insurance authorities moral hazard emerged gradually insured institutions operating under relatively premissive regulatory regimes were more prone to undertake risky lending activities than their more tightly regulated counterparts given the current system of deposit insurance the results suggest that effective regulation and supervision will play a key role in maintaining thrift stability in the 1990s copyright 1992 by american economic association

that s how we roll an experiment on rollover risk abstract we design a continuous time experiment to study how different short term credit maturities interact with the state of the economy we find that when the economy is in a boom long maturities stabilize the credit market yet when in a downturn such maturities increase the likelihood of credit freezes this result has important regulatory implications as it suggests that a policy aimed at reducing maturity mismatch in short term credit markets might backfire during a recession

deriving risk adjustment payment weights to maximize efficiency of health insurance markets risk adjustment is critical to the functioning of regulated health insurance markets to date estimation and evaluation of a risk adjustment model has been based on statistical rather than economic objective functions we develop a framework where the objective of risk adjustment is to minimize the efficiency loss from service level distortions due to adverse selection and we use the framework to develop a welfare grounded method for estimating risk adjustment weights we show that when the number of risk adjustor variables exceeds the number of decisions plans make about service allocations incentives for service level distortion can always be eliminated via a constrained least squares regression when the number of plan service level allocation decisions exceeds the number of risk adjusters the optimal weights can be found by an ols regression on a straightforward transformation of the data we illustrate this method with the data used to estimate risk adjustment payment weights in the netherlands n 16 5 million

risk selection and the specification of the conventional risk adjustment formula we argue that a sharp distinction must be made between the empirical problem of finding the best equation for explaining medical expenditures and the normative question of deriving capitations which give health plans the appropriate incentives we propose a procedure taken from the social choice literature to go from the estimated equations to the capitations if the estimated equations are not additively separable in legitimate and illegitimate risk adjusters it is impossible to remove all incentives for risk selection while respecting at the same time a straightforward requirement of horizontal equity this has immediate implications for the choice of the functional form moreover in so far as the conventional risk adjustment literature only includes so called legitimate risk adjusters in the estimations its results may suffer from omitted variables bias we illustrate our general methodological points with empirical results obtained from a cross section of 321 111 belgian patients

an experiment on the causes of bank run contagions abstract to understand the mechanisms behind bank run contagions we conduct bank run experiments in a modified diamond dybvig setup with two banks left and right the banks liquidity levels are either linked or independent left bank depositors see their bank s liquidity level before deciding right bank depositors only see left bank withdrawals before deciding we find that left bank depositors actions significantly affect right bank depositors behavior even when liquidities are independent furthermore a panic may be a one way street an increase in left bank withdrawals can cause a panic run on the right bank but a decrease does not calm depositors

premium subsidies for health insurance excessive coverage vs adverse selection the tax subsidy for employment related health insurance can lead to excessive coverage and excessive spending on medical care yet the potential also exists for adverse selection to result in the opposite problem insufficient coverage and underconsumption of medical care this paper uses the model of rothschild and stiglitz r s to show that a simple linear premium subsidy can correct market failure due to adverse selection the optimal linear subsidy balances welfare losses from excessive coverage against welfare gains from reduced adverse selection indeed a capped premium subsidy may mitigate adverse selection without creating incentives for excessive coverage

competition leverage how the demand side affects optimal risk adjustment we study optimal risk adjustment in imperfectly competitive health insurance markets when high risk consumers are less likely to switch insurer than low risk consumers insurers then have an incentive to select even if risk adjustment perfectly corrects for cost differences to achieve first best risk adjustment should overcompensate insurers for serving high risk agents second we identify a trade off between efficiency and consumer welfare reducing the difference in risk adjustment subsidies increases consumer welfare by leveraging competition from the elastic low risk market to the less elastic high risk market third mandatory pooling can increase consumer surplus further at the cost of efficiency

bank runs as coordination failures an experimental study we use experimental methods to investigate what factors contribute to breakdowns in coordination among a bank s depositors subjects in our experiment decide whether to leave their money deposited in a bank or withdraw it early a bank run occurs when there are too many early withdrawals we explore the effects of adding uncertainty about fundamental withdrawal demand and of changing the number of opportunities subjects have to withdraw our results show that i bank runs are rare when fundamental withdrawal demand is known but occur frequently when it is stochastic and ii subjects are more likely to withdraw when given multiple opportunities to do so than when presented with a single decision for the multiple opportunity case we evaluate individual withdrawal decisions according to a set of simple cutoff rules we find that the cutoff rule corresponding to the payoff dominant equilibrium of the game which involves bayesian updating of probabilities explains subject behavior better than other rules

bank suspension of convertibility abstract a banking panic occurs when depositors at all banks seek a large reduction in their deposit holdings suspension of convertibility of demand deposits into currency was the banking system s response to a banking panic when depositors are incompletely informed about the state of bank investments a panic can occur when depositors expect capital losses conditional on having observed noisy indicators of the state of bank investments banks with superior information about the investments can signal to depositors by suspending convertibility that continuation of the long term investments is mutually beneficial

optimal risk adjustment with adverse selection and spatial competition abstract paying insurers risk adjusted prices for covering different individuals can correct selection incentives and induce the market to provide optimal insurance policies to calculate the optimal risk adjusted prices we need to know a what the optimal policies are b how much they cost and c how competitive the market is we examine these issues in a model with spatial heterogeneity and adverse selection market equilibrium is characterized and delivery of the socially optimal insurance policies is possible as long as providers are paid risk adjusted fees for each individual they serve when the payment can be made on the basis of an individual s risk it should be sufficient to cover the expected cost of the socially optimal policy for that person plus a mark up if payments can be made only on the basis of a partially informative signal the optimal risk based payments should be adjusted according to a simple linear transformation identified by glazer and mcguire glazer j mcguire t 2000 optimal risk adjustment of health insurance premiums an application to managed care american economic review 90 4 1055 1071

risk in banking and capital regulation this paper investigates the role of bank capital regulation in risk control it is known that banks choose portfolios of higher risk because of inefficiently priced deposit insurance bank capital regulation is a way to redress this bias toward risk utilizing the mean variance model the following results are shown a the use of simple capital ratios in regulation is an ineffective means to bound the insolvency risk of banks b as a solution to problems of the capital ratio regulation the theoretically correct risk weights under the risk based capital plan are explicitly derived and c the theoretically correct risk weights are restrictions on asset composition which alters the optimal portfolio choice of banking firms the recent increase in bank failures especially after the 1980 and 1982 deregulatory acts has again ignited a controversy over the risk portfolio of the banking industry given the importance of this sector there has been increased scrutiny of the industry s motives for risk taking and possible regulatory changes to improve its stability these investigations have centered around two rather complementary areas the first of these is the role of deposit insurance and how its current pricing procedure encourages risk taking and justifies current bank regulations the works of buser chen and kane 4 kane 9 and benston et al 2 have made substantive contributions the authors demonstrates the way in which our current fixed rate insurance system rewards risk taking by the firm and insulates it through deposit insurance from the market discipline that needs to exist to ensure proper risk evaluation this realization has led these authors to propose a series of regulatory changes to encourage proper portfolio choice within the industry these include a shift to market value accounting risk based deposit insurance premiums and additional capital regulation the last of these serves as a method of coinsurance whereby higher capital levels require the bank to absorb greater losses in the event of failure and encourage additional prudence in management in essense it is one method of risk reduction that may offset the risk preference imposed on the industry due to the inappropriate insurance pricing because the amount of capital influences the probability of bank insolvency and thus the soundness of the entire banking system the regulators ceteris paribus prefer more capital to

reimbursing health plans and health providers efficiency in production versus selection the tradeoff between an insurer s or medical provider s incentives to select good risks and to produce efficiently is governed by the supply price analog to the demand price tradeoff between moral hazard and risk aversion under a variety of models the optimum supply price is a mixture of capitation and fee for service payments empirical literature shows that pure capitation payment leaves strong incentives for selection that are acted upon the presence of contracting costs in a rothschild stiglitz model means a limited pooling equilibrium can exist and that poor risks will not be at their preferred outcome

bank run psychology abstract banks are inherently susceptible to panics and bank runs due to the problem of maturity mismatch resulting in both a stable equilibrium in which the bank survives and an unstable equilibrium in which a bank run occurs understanding equilibrium selection in this setting is extremely important for safeguarding financial stability in this paper one new potential factor that determines whether a bank runs gets triggered or not is experimentally studied namely the psychological state of the depositor prior to participating in an experimental bank run game subjects are either induced with fear sadness or happiness using an autobiographical emotion induction task the findings suggest that the presence of background fear significantly increases the likelihood of withdrawal and a subsequent bank run in addition women are shown to be significantly more likely to withdraw then men but only in the fear induction treatment

federal deposit insurance regulatory policy and optimal bank capital this paper seeks to explain the combination of explicit and implicit pricing for deposit insurance employed by the fdic essentially the fdic sells two products insurance and regulation to span the product space it must and does set two prices we argue that the need to establish regulatory disincentives to bank risk taking is the heart of the controversy over the adequacy of bank capital and that the ability to close risky banks before exhausting their charter value i e the value of their right to continue in business stands at the center of these disincentives and in front of the fdic s insurance reserves just as a book shouldn t be judged by its cover a government agency shouldn t be judged by the words behind its initials with the fdic federal deposit insurance corporation the agency s name describes only part of its formal operations the fdic is quasi governmental has a regional structure and sells deposit insurance however the initials fail to convey the fdic s critical place in the governmental regulatory structure as the sole federal overseer of the approximately 8900 state chartered commercial banks that have chosen not to belong the federal reserve system reflecting the federal reserve s membership problem the number of these banks is growing year by year besides selling deposit insurance at bargain explicit rates the fdic performs four regulatory functions 1 entry regulation it passes on new banks applications for deposit insurance and on branch and merger proposals as well thereby protecting the value of existing bank charters 2 examination two thirds of fdic employees are concerned with inspecting bank records and supervising managerial activity 3 regulation of deposit rates and conditions for withdrawal by tradition fdic policies on these matters conform entirely with regulations applicable to federal reserve member banks and 4 disposition of failed banks when an insured bank fails the fdic usually chooses not to liquidate it 2

forward induction in coordination games abstract this paper provides experimental evidence on the power of forward induction arguments in a 2 2 coordination game allowing one player the option of obtaining a certain payoff instead of playing the game coordinates play in the direction predicted by the forward induction argument however two way pre play communication is a more effective coordination device

banking panics the role of the first come first served rule and information externalities this paper proposes that both the first come first served rule and information externalities are important in causing contagious bank runs the first come first served rule creates a negative payoff externality among depositors this payoff externality forces depositors to respond to early noisy information such as failures of other banks therefore failures of a few banks may trigger runs on other banks contagious runs may occur even if i depositors choose the pareto dominant equilibrium when there are multiple equilibria and ii the deposit contract is chosen to maximize depositor welfare the feasibility of reforming the fdic to impose market discipline is also investigated

the valuation of fdic deposit insurance using option pricing estimates when congress set the premium rate for fdic deposit insurance in the banking act of 1935 which authorized a permanent federal insurance system neither experience nor theory could offer much guidance regarding an appropriate fee structure although rates have since been periodically revised the fdic has yet to attempt to set the insurance rate at a ifair level that is a level equal to administrative costs plus the ex ante value of the insurance such a premium is the rate that would be charged by competitive private insurers however7 the garn st germain act of 1982 directed the fdic to consider the feasibility of a risk based premium structure in response the fdic has suggested a trial system in which each insured bank will be placed in one of three risk classes based on credit and interest rate risk relative to capital and a premium rate will be assigned to each group those rates will be determined in part by the loss experience of the entire banking system fdic 1983 another approach to the determination of the appropriate insurance premium has been offered by merton 1977 who suggested using the analogous relationship between deposit guarantees and put options to value fdic insurance in this paper we follow merton s suggestion and calculate bank specific estimates of the proper premium for deposit insurance for the banks in our sample we find that fdic rates greatly exceed estimates of the fair value of the insurance derived from the blackscholes 1972 option pricing model

on the oligopolistic extraction of non renewable common pool resources in recent literature the extraction of common pool resources ha s been discussed under the aspect of whether or not they can be used efficiently when a finite number of agents has access to the resource the objective of this paper is the derivation of a necessary equilibrium condition in a simple model this condition has severe consequences for existence propositions in papers of m c kemp and n v long 1980 j mcmillan and h w sinn 1984 and j f reinganum and n l stokey 1985 copyright 1986 by the review of economic studies limited

efficiency inducing tax for a common property oligopoly the author characterizes the markov perfect tax that induces a common property oligopoly to extract efficiently a nonrenewable resource for linear and isoelastic demand he provides closed form expressions of the unique specific tax industry profits may be higher or lower in the oligopoly with the tax relative to the competitive equilibrium with property rights for linear or isoelastic demand there exists no feasible open loop tax that induces efficient extraction in this case the policymaker gains no advantage from being able to make binding commitments copyright 1992 by royal economic society

capital requirements and the behaviour of commercial banks abstract i study the consequences of capital regulations on the portfolio choices of commercial banks elaborating on previous work by kareken and wallace 1978 koehn and santomero 1980 and kim and santomero 1988 i obtain the following results if the objective of commercial banks is maximization of the market value of their future profits value maximizing banks capital regulations cannot prevent banks from choosing very specialized and very risky portfolios risk based insurance premia are in fact the relevant instrument for that purpose on the other hand if banks behave as portfolio managers utility maximizing banks capital regulations can be effective but only if the weights used in the computation of the ratio are proportional to the systematic risks of the assets their betas because of limited liability of commercial banks a minimum capital regulation or a closing rule may become necessary as well to prevent failing banks from betting for resurrection

on freezing depositor funds at financially distressed banks an experimental analysis this article reports an experiment conducted to evaluate the effects of alterations in the terms of repayments to depositors following a liquidity suspension as well as the effect of alterations in the publicity of information about withdrawal behavior on the fragility of distressed banks results indicate that a tough renegotiation stance of protecting depositors who maintain their money in the bank can quite effectively promote stability information provided to depositors regarding past withdrawal behavior weakens the effectiveness of a tough renegotiation policy but reduces fragility somewhat for a more lenient rescheduling condition

the structure of a contract and the theory of a non exclusive resource the process of arriving at a useful concept of analysis is not only slow and painful but also may go astray and attain nothing useful someone begins with one example or observation followed by a theory which is intuitively plausible a theoretical term associated with a vague concept is coined examples of a seemingly different type emerge which call for another theory the process goes on as examples and theories continue to accumulate the different categories under the same heading of analysis serve only to confuse and each associated theory becomes ad hoc such has been the fate of the concept of externality a more useful approach i think is via contractual conditions the example chosen for illustration is marine fisheries where the fishing right is taken

a reexamination of mean variance analysis of bank capital regulation abstract the mean variance framework has been used to analyze the effects of bank capital regulation on the asset and bankruptcy risk of insured utility maximizing banks this literature claims that more stringent capital regulation will increase asset risk and can increase bankruptcy risk these conclusions are notable because they are opposite to those obtained for insured value maximizing banks in this paper we show that the utility maximization literature does not support its conclusions regarding the effects of bank capital regulation because it has mischaracterized the bank s investment opportunity set by neglecting the option value of deposit insurance

setting health plan premiums to ensure efficient quality in health care minimum variance optimal risk adjustment abstract risk adjustment refers to the practice of paying health plans a premium per person or per family based on a formula using risk adjusters such as age or gender and weights on those adjusters one role of risk adjustment is to make sure plans have an incentive to accept all potential enrollees another role at least as important in our view is to lead health plans to choose the efficient level of quality of care for the various services they offer most of the research and policy literature on risk adjustment focuses on the first problem this paper proposes a new way to calculate weights in a risk adjustment formula that contends with both problems for a given set of adjusters we identify the weights that minimize the variance in plan predictable health care costs that are not explained by risk adjustment addressing the access problem subject to the payments satisfying conditions for an optimal risk adjuster making sure plans provide the efficient quality we call the formula minimum variance optimal risk adjustment mvora

impact of the financial crisis on bank run risk danger of the days after abstract we examine the developments of depositor knowledge attitudes and behavior throughout the recent financial crisis and discuss their impact on bank run risk based on a self collected data set surveying depositors before 2007 at 2008 and after the peak of the crisis 2009 we observe a worrying dynamic pattern at the peak depositors knew more about deposit insurance placed more importance on deposit security and slightly raised their deposits however in the aftermath of the crisis the enhanced depositor knowledge proved to be non permanent while the increased importance of deposit security and the exposure of depositors persisted the proportion of completely uninformed strongly involved and highly exposed depositors who carry the highest risk of triggering a bank run was reduced around the peak of the crisis but rebounded strongly afterwards even exceeding pre crisis levels these findings point to a higher bank run risk in the aftermath than during the financial crisis

rational and self fulfilling balance of payments crises speculative attacks on a pegged exchange rate must sometimes occur ifasset price paths are to be free of abnormal profit opportunities suchattacks are fully rational as they reflect the market s response to aregime breakdown that is inevitable the authors shows that under someexpectations about policy balance of payments crises can also be purely self fulfilling events in such cases even a permanently viableregime may collapse and the economy will possess multiple equilibriacorresponding to different subjective assessments of the probability ofa crisis the behavior of the domestic interest rate will naturally reflect the possibility of a speculative attack copyright 1986 by american economic association

experimental evidence of bank runs as pure coordination failures abstract we investigate how coordination requirement measured by the coordination parameter affects the occurrence of miscoordination based bank runs in controlled laboratory environments we identify an indeterminacy region of the coordination parameter such that games with the parameter within the region have varying coordination outcomes and exhibit persistent path dependence experimental economies with the parameter above below the region stay close or converge to the run non run equilibrium switches between the two equilibria occur even with fixed economic fundamentals the experimental results are well accounted for by a version of the evolutionary algorithm that uses experimentation rates estimated from the experimental data

appropriation of common access natural resources through exploration the relevance of the open loop concept in this paper the open loop equilibrium is rehabilitated as a sensible concept for analyzing common property situations in a model of natur al resource exploration in which the sole motivation to explore prior to extraction arises from a strategic incentive to preempt competito rs a consistency rule to the exploration game is applied under which the commonality of reserves is preserved even if strategies are open loop under this rule the so often claimed efficiency of the common property open loop equilibrium is lost copyright 1988 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

a reexamination of the over or under pricing of deposit insurance this study shows how fair deposit insurance premia can be calculated using data on bank stock prices interest rate movements and income and balance sheet accounts fair insurance premia are estimat ed under the alternative assumptions that the fdic provides either a limited term variable rate or unlimited term insurance cont ract to banks the paper s results suggest that for nearly all of the large commerical banks in the sample the actual insurance premium c harged by the fdic falls between the bounds of fair limited term and unlimited term insurance premia copyright 1987 by ohio state university press

on the effects of deposit insurance and observability on bank runs an experimental study we study the effects of deposit insurance and observability of previous actions on the emergence of bank runs by means of a controlled laboratory experiment we consider three depositors in the line of a bank who decide between withdrawing or keeping their money deposited we have three treatments with different levels of deposit insurance which reflect the losses a depositor may incur in the case of a bank run we find that different levels of deposit insurance and the possibility of observing other depositors actions affect the likelihood of bank runs when decisions are not observable higher levels of deposit insurance decrease the probability of bank runs when decisions are observable this need not to be the case these results suggest that i observability might be considered as a partial substitute of deposit insurance and ii the optimal deposit insurance should take into account the degree of observability

optimal risk adjustment in markets with adverse selection an application to managed care it is well known that adverse selection causes distortions in contracts in markets with asymmetric information taxing inefficient contracts and subsidizing the efficient ones can improve market outcomes bruce c greenwald and joseph e stiglitz 1986 although regulators rarely seem to implement tax and subsidy schemes with adverse selection motives in mind contracts are often complex and incomplete and it is the inefficient elements of the contract that are difficult to verify and hence tax or subsidize this is precisely the reason that in health insurance markets rather than subsidizing contracts regulators and payers contend with adverse selection by taxing and subsidizing the price paid to insuring health plans on the basis of observable characteristics of the persons joining the plan a practice known as risk adjustment risk adjusted premiums are paid to managed care plans plans that ration care by management rather than by conventional approaches like coinsurance and deductibles and offer a bundle of characteristics quality access for many services that is fundamentally outside the scope of direct regulation selection related incentives threaten the efficiency and fairness of this organization of health insurance markets by inducing plans to distort the quality of the services they offer to discourage high cost persons from joining the plan as managed care becomes the predominant source of health care for residents of the united states and many other countries payers attempt to address this incentive by setting a risk adjusted price that pays more for more expensive enrollees as it is conventionally practiced risk adjustment sets prices for people proportional to their expected cost based on observable characteristics the federal medicare program for example has used age sex welfare status and county of residence adjusters to set prices to managed care plans to convey how what we term conventional risk adjustment works suppose age is the risk adjuster for a medicare population over 65 if it is determined that the 75to 84 year old population costs 20 percent more than the overall average in medicare the assumption in conventional risk adjustment is that the premium paid to plans for someone in this group should be 20 percent above the average we fundamentally disagree that this is the right way to think about and do risk adjustment

dynamic demand and noncompetitive intertemporal output adjustments abstract this paper integrates dynamics on the demand and on the supply side which are characteristic for many goods in particular fuels due to costly adjustments furthermore firms often pursue a quantity strategy and decide on output adjustments additional capacities etc instead of fixing prices e g opec moved from posting prices to adjusting output in 1986 this paper provides a corresponding framework surprisingly ignored in the literature and derives intertemporal market equilibria cooperative and noncooperative in open loop and in markov strategies the equilibrium in markov strategies is different mostly opposite to the much discussed sticky price models the qualitative properties are non trivial and some of them are even surprising e g increased demand sluggishness can raise supply

deposit insurance and risk taking behavior in the credit union industry abstract this paper examines the relationship between deposit insurance and risk taking behavior within the credit union industry time series tests employing industry average financial ratios for federal and state credit unions did not support the increased risk taking hypothesis although federal credit union capital declined immediately following the adoption of deposit insurance this was most likely the result of reduced capital requirements not deposit insurance liquidity and loan delinquency ratios had a negative time trend coefficient implying a decline in risk taking behavior during the post insurance period cross sectional test results employing iowa state chartered credit union data indicated that insured credit unions were better capitalized and more liquid than their uninsured counterparts overall there was no evidence that the adoption of deposit insurance increased the risk taking behavior of credit unions

equilibrium bank runs we analyze a banking system in which the class of feasible deposit contracts or mechanisms is broad the mechanisms must satisfy a sequential service constraint but partial or full suspension of convertibility is allowed consumers must be willing to deposit ex ante we show by examples that under the so called optimal contract the postdeposit game can have a run equilibrium given a propensity to run triggered by sunspots the optimal contract for the full predeposit game can be consistent with runs that occur with positive probability thus the diamond dybvig framework can explain bank runs as emerging in equilibrium under the optimal deposit contract

an experimental exploration of self fulfilling banking panics their occurrence persistence and prevention this article tests the possibility and the degree of persistence of self fulfilling banking panics through an experimental protocol panics are proved to be persistent phenomena that are difficult to prevent however it seems possible to curb them through a learning effect caused by a temporary but sufficient suspension of the deposit availability combined with a narrow banking solution which makes banks more liquid additionally panic prevention requires a full deposit coverage to be effective this suggests that the moral hazard issue should not be tackled through a lower deposit coverage especially in emerging countries banking systems where depositors are likely to lose confidence

a comparison of alternative models for the demand for medical care we have tested alternative models of the demand for medical care using experimental data the estimated response of demand to insurance plan is sensitive to the model used we therefore use a split sample analysis and find that a model that more closely approximates distributional assumptions and uses a nonparametric retransformation factor performs better in terms of mean squared forecast error simpler models are inferior either because they are not robust to outliers e g anova anocova or because they are inconsistent when strong distributional assumptions are violated e g a two parameter box cox transformation

oligopoly extraction of a common property natural resource the importance of the period of commitment in dynamic games the theory of noncooperative dynamic games has provided an extremely powerful framework for studying many of the classic questions in industrial organization for example questions about resource extraction advertising research and development investment in new capacity and barriers to entry where interactions over time among few firms are involved however an important methodological issue arises when economic competition over time is modeled as a dynamic game the issue is the appropriate formulation of the players strategy spaces

strategic loan defaults and coordination an experimental analysis this paper experimentally studies the impact of bank and borrower fundamentals on loan repayment we find that solvent borrowers are more likely to default strategically when the bank s expected strength is low although loan repayment is a pareto dominant nash equilibrium borrowers are also less likely to repay when other borrowers expected repayment capacity is low regardless of banks fundamentals we show that changes in expectations about bank and borrower fundamentals change the risk dominance properties of the borrowers coordination problem and that these changes subsequently explain strategic defaults for the individual borrower loss aversion and negative past experiences reduce repayment suggesting that bank failure can be contagious in times of distress

a model of the impact of reimbursement schemes on health plan choice flat capitation uniform prospective payments makes enrolling healthy enrollees profitable to health plans plans with relatively generous benefits may attract the sick and fail through a premium spiral we simulate a model of idealized managed competition to explore the effect on market performance of alternatives to flat capitation such as severity adjusted capitation and reduced supply side cost sharing in our model flat capitation causes severe market problems severity adjustment and to a lesser extent reduced supply side cost sharing improve market performance but outcomes are efficient only in cases in which people bear the marginal costs of their choices