information acquisition and under diversification if an investor wants to form a portfolio of risky assets and can exert effort to collect information on the future value of these assets before he invests which assets should he learn about the best assets to acquire information about are ones the investor expects to hold but the assets the investor holds depend on the information he observes we build a framework to solve jointly for investment and information choices with general preferences and information cost functions although the optimal research strategies depend on preferences and costs the main result is that the investor who can first collect information systematically deviates from holding a diversified portfolio information acquisition can rationalize investing in a diversified fund and a concentrated set of assets an allocation often observed but usually deemed anomalous copyright wiley blackwell

a country specific point of view on international diversification abstract this paper adds a country specific point of view on diversification among financial markets previous results indicate that emerging markets may generally exhibit higher diversification effects in comparison to developed markets due to lower market linkages however the question remains which markets in particular may be more or less attractive among emerging and developed markets as well as in a world market setting to the best of our knowledge this is the first empirical study which analyzes this question beyond continental levels only we analyze diversification by means of optimal portfolio allocations and in terms of tail risk reductions we also include investors tendency to overweight regional investments home bias our results show that malaysia switzerland jordan chile or singapore are markets with high diversification potential on the contrary argentina brazil and south korea exhibit high individual risk levels in combination with high market linkages

is international diversification really beneficial abstract previous research claims that low constant correlations among international stock indices create substantial risk reduction from diversification we contend that only using constant correlations is too simplistic an approach we examine international diversification by 1 using conditional correlations 2 evaluating tail risk including the effect of skewness and kurtosis and 3 examining the possible tradeoffs of standard deviation with correlation skewness and kurtosis we show that conclusions concerning diversification based solely on constant correlations across markets can be misleading since the diversification benefits are time varying are affected by non normality and depend on the benchmark country employed finally tradeoffs do exist between standard deviation and the other risk factors

unobservable shocks as carriers of contagion we propose an identified structural garch model to disentangle the dynamics of financial market crises we distinguish between the hypersensitivity of a domestic market in crisis to news from foreign non crisis markets and the contagion imported to a tranquil domestic market from foreign crises the model also enables us to connect unobserved structural shocks with their source markets using variance decompositions and to compare the size and dynamics of impulses during crises periods with tranquil period impulses to illustrate we apply the method to data from the 1997 1998 asian financial crisis which consists of a complicated set of interacting crises we find significant hypersensitivity and contagion between these markets but also show that links may strengthen or weaken impulse response functions for an equally weighted equity portfolio show the increasing dominance of korean and hong kong shocks during the crises and covariance responses demonstrate multiple layers of contagion effects

is volatility clustering of asset returns asymmetric abstract volatility clustering is a well known stylized feature of financial asset returns this paper investigates asymmetric pattern in volatility clustering by employing a univariate copula approach of chen and fan 2006 using daily realized kernel volatilities constructed from high frequency data from stock and foreign exchange markets we find evidence that volatility clustering is highly nonlinear and strongly asymmetric in that clusters of high volatility occur more often than clusters of low volatility to the best of our knowledge this paper is the first one to address and uncover this phenomenon in particular the asymmetry in volatility clustering is found to be more pronounced in the stock markets than in the foreign exchange markets further the volatility clusters are shown to remain persistent for over a month and asymmetric across different time periods our findings have important implications for risk management a simulation study indicates that models which accommodate asymmetric volatility clustering can significantly improve the out of sample forecasts of value at risk

comovement in international equity markets a sectoral view abstract we investigate shifts in correlation patterns among international equity returns at the market level as well as the industry level we develop a novel bivariate garch model for equity returns with a smoothly time varying correlation and then derive a lagrange multiplier statistic to test the constant correlation hypothesis directly applying the test to weekly data from germany japan the uk and the us in the period 1980 2000 we find that correlations among the german uk and us stock markets have doubled whereas japanese correlations have remained the same both dates of change and speeds of adjustment vary widely across countries and sectors

a strategic market game with complete markets abstract an exchange economy is modeled as a strategic market game with all pairwise markets available existence of noncooperative equilibria is proved it is shown that if resources are distributed in a skewed manner in equilibrium prices may not satisfy the no arbitrage condition one round of trade even with all goods serving as money is not sufficient to provide enough liquidity for efficient trade

trying to explain home bias in equities and consumption investors hold a substantially larger proportion of their wealth portfolios in domestic assets than standard portfolio theory would suggest a phenomenon called equity home bias in the absence of this bias investors would optimally diversify domestic output risk using foreign equities therefore consumption growth rates would tend to co move across countries even when output growth rates do not empirically however consumption growth rates tend to have a lower correlation across countries than do output growth rates a phenomenon i call consumption home bias in this paper i discuss these two biases and their potential relationship as suggested by the literature

securitisation and financial stability a widespread opinion before the credit crisis of 2007 8 was that securitisation enhances financial stability by dispersing credit risk after the credit crisis securitisation was blamed for allowing the hot potato of bad loans to be passed to unsuspecting investors both views miss the endogeneity of credit supply securitisation enables credit expansion through higher leverage of the financial system as a whole securitisation by itself may not enhance financial stability if the imperative to expand assets drives down lending standards the hot potato of bad loans sits in the financial system on the balance sheets of large banks rather than being sold on to final investors since the aim of financial intermediaries is to expand lending in order to utilise slack in balance sheet capacity

the structure and degree of dependence a quantile regression approach abstract the copula function defines the degree of dependence and the structure of dependence this paper proposes an alternative framework to decompose the dependence using quantile regression we demonstrate that the methodology provides a detailed picture of dependence including asymmetric and non linear relationships in addition changes in the degree or structure of dependence can be modeled and tested for each quantile of the distribution the empirical part applies the framework to three different sets of financial time series and demonstrates substantial differences in dependence patterns among asset classes and through time the analysis of 54 global equity markets shows that detailed information about the structure of dependence is crucial to adequately assess the benefits of diversification in normal times and crisis times

information markets and the comovement of asset prices traditional asset pricing models predict that covariance between prices of difierent assets should be lower than what we observe in the data this model generates high covariance within a rational expectations framework by introducing markets for information about asset payofis when information is costly rational investors will not buy information about all assets they will learn about a subset because information production has high flxed costs competitive producers charge more for low demand information than for high demand information a price that declines in quantity makes investors want to purchase a common subset of information if investors price many assets using a common subset of information then a shock to one signal is passed on as a common shock to many asset prices these common shocks to asset prices generate excess covariance the cross sectional and time series properties of asset price covariance are consistent with this explanation

the limits of diversification when losses may be large abstract recent results in value at risk analysis show that for extremely heavy tailed risks with unbounded distribution support diversification may increase value at risk and that generally it is difficult to construct an appropriate risk measure for such distributions we further analyze the limitations of diversification for heavy tailed risks we provide additional insight in two ways first we show that similar non diversification results are valid for a large class of risks with bounded support as long as the risks are concentrated on a sufficiently large interval the required length of the support depends on the number of risks available and on the degree of heavy tailedness second we relate the value at risk approach to more general risk frameworks we argue that in markets for risky assets where the number of assets is limited compared with the bounded distribution support of the risks unbounded heavy tailed risks may provide a reasonable approximation we suggest that this type of analysis may have a role in explaining various types of market failures in markets for assets with possibly large negative outcomes

international diversification strategies revisited from the risk perspective following roll roll r 1992 industrial structure and comparative behaviour of international stock market indices journal of finance 47 3 42 and heston and rouwenhorst heston s l rouwenhorst g k 1994 does industrial structure explain the benefits of international diversification journal of financial economics 36 3 27 researchers have decomposed stock returns into country and industry components evidence suggests that industry components have become more important in recent years but the reasons for this are unclear existing research concentrated mainly on stock returns in industrial countries in this paper we consider instead the decomposition of stock risks within emerging equity markets we provide a rationale for this procedure and its relationship to return decompositions the results provide new firm specific evidence on the debate over country and industry components their stability over time and the implications for portfolio diversification

contagion as a domino effect in global stock markets this paper shows that stock market contagion occurs as a domino effect where confined local crashes evolve into more widespread crashes using a novel framework based on ordered logit regressions we model the occurrence of local regional and global crashes as a function of their past occurrences and financial variables we find significant evidence that global crashes do not occur abruptly but are preceded by local and regional crashes besides this form of contagion interdependence shows up by the effect of interest rates bond returns and stock market volatility on crash probabilities when it comes to forecasting global crashes our model outperforms a binomial model for global crashes only

international diversification an extreme value approach abstract international diversification has costs and benefits depending on the degree of asset dependence we study international diversification with two dependence measures correlations and extreme dependence we discover that dependence has typically increased over time and document mixed evidence on heavy tails in individual countries moreover we uncover three additional findings related to dependence first the timing of downside risk differs depending on the region surprisingly recent latin american returns exhibit little downside risk second latin america exhibits a great deal of correlation complexity third according to the empirical results correlation does not vary with returns but extreme dependence does vary monotonically with regional returns our results are consistent with a tradeoff between international diversification and systemic risk they also suggest international limits to diversification and that international investors demand some compensation for joint downside risk during extreme events

toward a presumption of efficiency in politics in the preceding pages i have returned time and again to the idea that in the next quarter century the profession will devote more of its resources to an understanding of politics and of political organizations with a presumption that the behaviors and institutions we observe in the real world represent efficient responses to exogenously given constraints and to competitive forces that does not mean of course that normative preoccupations critical evaluations and reformist drives will not continue to motivate a good number of scholars that is to be expected and praised however i believe that in relative terms more attention will come to be given to understanding and less to re designing and reforming in this context the economic approach to politics will flourish and as an important carrier of these research results public choice will continue to play an indispensable role we can already see the future and it is promising

the copula garch model of conditional dependencies an international stock market application abstract modeling the dependency between stock market returns is a difficult task when returns follow a complicated dynamics when returns are non normal it is often simply impossible to specify the multivariate distribution relating two or more return series in this context we propose a new methodology based on copula functions which consists in estimating first the univariate distributions and then the joining distribution in such a context the dependency parameter can easily be rendered conditional and time varying we apply this methodology to the daily returns of four major stock markets our results suggest that conditional dependency depends on past realizations for european market pairs only for these markets dependency is found to be more widely affected when returns move in the same direction than when they move in opposite directions modeling the dynamics of the dependency parameter also suggests that dependency is higher and more persistent between european stock markets

do food and oil prices co move abstract this paper studies co movements between world oil prices and global prices for corn soybean and wheat using copulas several copula models with different conditional dependence structures and time varying dependence parameters were considered empirical results for weekly data from january 1998 to april 2011 showed weak oil food dependence and no extreme market dependence between oil and food prices these results support the neutrality of agricultural commodity markets to the effects of changes in oil prices and non contagion between the crude oil and agricultural markets however dependence increased significantly in the last three years of the sampling period even though upper tail dependence remained insignificant indicating that food price spikes are not caused by positive extreme oil price changes these results have implications for policy design risk management and hedging strategies

dependence structure between the equity market and the foreign exchange market a copula approach abstract this paper investigates the dependence structure between the equity market and the foreign exchange market by using copulas in particular several copulas with different dependence structure are compared and used to directly model the underlying dependence structure we find that there exists significant symmetric upper and lower tail dependence between the two financial markets and the dependence remains significant but weaker after the launch of the euro our findings have important implications for both global investment risk management and international asset pricing by taking into account joint tail risk

portfolio optimization in the presence of dependent financial returns with long memory a copula based approach abstract in this paper we seek to examine the effect of the presence of long memory on the dependence structure between financial returns and on portfolio optimization first we focus on the dependence structure using copulas to select the best copula in addition to the goodness of fit tests we employ a graphical method based on visual comparison of the fitted copula density and the smoothed copula density estimated by wavelets moreover we check the stability of the copula parameter the empirical results show that the long memory affects the dependence structure second we analyze the impact of this dependence structure on the optimal portfolio we propose a new approach based on minimizing the conditional value at risk and assuming that the dependence structure is modeled by the copula parameter the empirical results show that our approach outperforms the traditional minimizing variance approach where the dependence structure is represented by the linear correlation coefficient

strategic market games with exchange rates abstract strategic market games describe mechanisms of formation of prices and of redistribution of goods we introduce here a model without commodity money but where the use of fiat money does not imply the possibility of debt hence the necessity for penalty this is done through a collection of exchange rates that allows for a coherent price system and a redistribution that clears the market for any initial bids of the agents journal of economic literature classification numbers c72 d51 e31

commodity and equity markets some stylized facts from a copula approach abstract in this paper we propose to identify the dependence structure that exists between returns on equity and commodity futures and its development over the past 20 years the key point is that we do not impose any dependence structure but let the data select it to do so we model the dependence between commodity metal agriculture and energy and stock markets using a flexible approach that allows us to investigate whether the co movement is i symmetrical and frequent ii a symmetrical and mostly present during extreme events and iii asymmetrical and mostly present during extreme events we also allow for this dependence to be time varying from january 1990 to february 2012 our analysis uncovers three major stylised facts first we find that the dependence between commodity and stock markets is time varying symmetrical and occurs most of the time as opposed to mostly during extreme events second not allowing for time varying parameters in the dependence distribution generates a bias towards an evidence of tail dependence similarly considering only tail dependence may lead to false evidence of asymmetry third a growing co movement between industrial metals and equity markets is identified as early as 2003 this co movement spreads to all commodity classes and becomes unambiguously stronger with the global financial crisis after fall 2008

economic and political foundations of tax structure this paper derives the essential elements of tax systems as the outcome of rational behavior in a model w here government maximizes expected support and where opposition to ta xation depends on the loss in full income the analysis treats the le vel of expenditures as endogenous and integrates the influence of adm inistration costs with that of political and economic factors tax st ructure is shown to be a system of related components in equilibrium a final section compares results to two alternative approaches opti mal taxation and the leviathan model copyright 1988 by american economic association

extreme dependence with asymmetric thresholds evidence for the european monetary union abstract existing papers on extreme dependence use symmetrical thresholds to define simultaneous stock market booms or crashes such as the joint occurrence of the upper or lower one percent return quantile in both stock markets we show that the probability of the joint occurrence of extreme stock returns may be higher for asymmetric thresholds than for symmetric thresholds we propose a non parametric measure of extreme dependence which allows capturing extreme events for different thresholds and can be used to compute different types of extreme dependence we find that extreme dependence among the stock markets of ten initial emu member countries the united kingdom and the united states is largely asymmetrical in the pre emu period 1989 1998 and largely symmetrical in the emu period 1999 2010 our findings suggest that ignoring the possibility of asymmetric extreme dependence may lead to an underestimation of the probability of co booms and co crashes

household portfolio diversification a case for rank dependent preferences the proliferation of novel preference theories in financial economics is hampered by a lack of non experimental evidence and by the theories additional complexity which has not been shown to be critical in applications in this article i present arguments in support of preferences with rank dependency using the survey of consumer finances data i document two widespread patterns inconsistent with expected utility i many households simultaneously invest in well deversified funds and in poorly diversified portfolios of stocks and ii some households with substantial savings do not invest anything in equities i show that portfolio choice models with rank dependent preferences plausibly parameterized and under fully rational assumptions are quantitatively consistent with the observed diversification these results call for further efforts to integrate the models of rank dependent preferences in portfolio theory and asset pricing the decision theoretic literature has long acknowledged the shortcomings of the expected utility theory of von neumann and morgenstern 1944 several generalizations of the theory are inspired by the experimental evidence and aimed at improving its descriptive accuracy however there are few applications of new models of preferences in finance and expected utility continues to dominate the field 1 two principal hurdles slow the proliferation of novel preferences in financial economics first the lack of empirical non experimental or field data confirming that the behavior motivating non expected utilities is widespread outside the laboratory settings second the additional and often significant complexity of the alternative preferences which has not been shown to be critical in applications where the models based on expected utility fall short of reasonable predictions this article presents empirical and theoretical this paper was previously circulated under the title household portfolio diversification the paper has benefited from the comments of shlomo benartzi luca benzoni markus brunnermeier john dickhaut maria perozek raj singh hersh shefrin and workshop participants at minnesota finance bag lunch 2003 wharton conference household financial decision making and portfolio choice and 2003 summer meetings of econometric society i would like to thank cam harvey the editor and an anonymous referee for many helpful comments and suggestions a special thanks to jack kareken for comments and editorial help on an earlier draft i am grateful to donna zerwitz for editorial assistance the views expressed herein are those of the author and not necessarily of the federal reserve bank of minneapolis or the federal reserve system all errors and omissions are the sole responsibility of the author address correspondence to valery polkovnichenko finance 3 122 csom 319 19 th

ratings shopping and asset complexity a theory of ratings inflation abstract many identify inflated credit ratings as one contributor to the recent financial market turmoil we develop an equilibrium model of the market for ratings and use it to examine possible origins of and cures for ratings inflation in the model asset issuers can shop for ratings observe multiple ratings and disclose only the most favorable before auctioning their assets when assets are simple agencies ratings are similar and the incentive to ratings shop is low when assets are sufficiently complex ratings differ enough that an incentive to shop emerges thus an increase in the complexity of recently issued securities could create a systematic bias in disclosed ratings despite the fact that each ratings agency produces an unbiased estimate of the asset s true quality increasing competition among agencies would only worsen this problem switching to an investor initiated ratings system alleviates the bias but could collapse the market for information

international diversification a copula approach abstract the viability of international diversification involves balancing benefits and costs this balance hinges on the degree of asset dependence in light of theoretical research linking diversification and dependence we examine international diversification using two measures of dependence correlations and copulas we document several findings first dependence has increased over time second we find evidence of asymmetric dependence or downside risk in latin america but less in the g5 the results indicate very little downside risk in east asia third east asian and latin american returns exhibit some correlation complexity interestingly the regions with maximal dependence or worst diversification do not command large returns our results suggest international limits to diversification they are also consistent with a possible tradeoff between international diversification and systemic risk

the dark side of global integration increasing tail dependence abstract we measure stock market coexceedances using the methodology of cappiello gerard and manganelli 2005 ecb working paper 501 this method enables us to measure comovement at each point of the return distribution first we construct annual coexceedance probabilities for both lower and upper tail return quantiles using daily data from 1974 2006 next we explain these probabilities in a panel gravity model framework results show that macroeconomic variables asymmetrically impact stock market comovement across the return distribution financial liberalization significantly increases left tail comovement whereas trade integration significantly increases comovement across all quantiles decreasing exchange rate volatility results in increasing lower tail comovement the introduction of the euro increases comovement across the entire return distribution thereby significantly reducing the benefits of portfolio diversification within the euro area

three minimal market institutions with human and algorithmic agents theory and experimental evidence we define and examine the performance of three minimal strategic market games sell all buy sell and double auction in laboratory relative to the predictions of theory unlike open or partial equilibrium settings of most other experiments these closed exchange economies have limited amounts of cash to facilitate transactions and include feedback general equilibrium theory since it abstracts away from market mechanisms and has no role for money or credit makes no predictions about how the paths of convergence to the competitive equilibrium may differ across alternative mechanisms

liquid markets and competition abstract a market is liquid if no individual s actions have a big effect on the prices of goods traded in that market perfectly competitive markets are therefore perfectly liquid it is well known that market liquidity can be achieved by increasing the number of traders so that individual trades are small compared to total trades we show that even when there are only few traders market liquidity can be achieved through large short sales in which net trades are small relative to gross trades in particular for a natural variant of the market game which permits unlimited short sales we show that there is always a nash equilibrium allocation arbitrarily close to a competitive equilibrium allocation of course not all ne are near competitive only the large short sales ne are nearly liquid and hence close to ce