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This paper examines how wealth accumulation and risk sharing affect the evolution of inequality over time. We first assume risk sharing away and examine how inequality evolves over time when agents accumulate an asset. If asset accumulation is unbounded and the asset yields a positive return, inequality converges to single value over time. If the asset yields a zero or negative return (e.g., grain storage), there is no persistent inequality but inequality is nevertheless correlated over time. If wealth yields a positive return but is in finite supply (e.g., land), persistent inequality arises if one agent is more thrifty than the other. Multiple equilibria may obtain. Societies might prevent polarization by closing down markets in such assets. We then introduce risk sharing. With perfect risk sharing, welfare inequality is constant across time. For continued participation to mutual insurance to be voluntary, asset inequality must remain 'close' to welfare inequality. With imperfect commitment, the end result is a hybrid situation half-way between the risk sharing model and the pure accumulation model. If risk aversion is high for poor agents but low for rich ones, patronage arises whereby the rich on average take away from the poor.

We define a class of risk-taking-neutral (RTN) background risks. These background risks have the property that they will not alter decisions made with respect to another risk, for individuals with HARA utility. If we wish to compare a decision made with and without some exogenous background risk, it is often easier to compare the decision made to one made with a RTN background risk. We use this methodology to prove and extend a well-known theorem about dynamic investment strategy, due to Mossin (1968a). We also use this methodology to analyze investment behavior in the presence of an income tax as well as to analyze investment behavior in the presence of particular types of background risks.

This paper examines how segmented asset markets can generate real and nominal effects of monetary policy. I develop a model, in which varieties of consumption bundles are purchased sequentially. Newly injected money thus disseminates slowly through the economy via second-round effects and induces a longer-lasting, non-degenerate wealth distribution. As a result, the demand elasticity differs across consumers, affecting optimal markups chosen by producers. The model predicts a short-term inflation-output trade-off, a liquidity effect, countercyclical markups, and procyclical wages and expenditure dispersion across consumers after monetary shocks. Including a modest degree of real or nominal wage rigidity yields responses that are also quantitatively in line with empirical evidence.

In this paper, a model of bounded rational investors investing their portfolio in a passive investment vehicle (e.g., an Exchange Traded Fund replicating a broad index) or an actively managed fund is presented. The model proposes that the quick reswitching of these short-term oriented investors induces momentum behavior in prices. Investors prefer passsive funds in time of low risk-free rates and when active funds charge high management costs. Actively managed funds have a lower volatility but are only able to outperform the passive funds in downturns. Simulations confirm the emergence of two regimes: a regime where prices are close to fundamentals and another regime with a positive bubble. The size and the length of this bubble increases for low market liquidity and high switching speed of investors. The market volatility increases for strong reswitching activities and short-term thinking of bounded rational investors. Negative bubbles (market prices lower than fundamentals) tend to occur if active portfolio managers exhibit high risk aversion, but are less frequent than positive bubbles.

This paper investigates the long-term impact of price-level targeting on social welfare in an overlapping generations model in which the young save for old age by investing in productive capital and indexed and nominal government bonds. A key feature of the model is that the extent of bond indexation is determined endogenously in response to monetary policy as part of an optimal commitment Ramsey policy. Due to the absence of base-level drift under price-level targeting, long-term inflation risk is reduced by an order of magnitude compared to inflation targeting. Consequently, real bond returns are stabilised somewhat, and consumption volatility for old generations is reduced by around 15 per cent. The baseline welfare gain from price- level targeting is equivalent to a permanent increase in aggregate consumption of only 0.01 per cent, but this estimate is strongly sensitive on the upside.

In this paper, we show that in a model where investors have heterogeneous preferences, the expected return of risky assets depends on the idiosyncratic coskewness beta, which measures the co-movement of the individual stock variance and the market return. We find that there is a negative (positive) relation between idiosyncratic coskewness and equity returns when idiosyncratic coskewness betas are positive (negative). Standard risk factors, such as the market, size, book-to-market, and momentum cannot explain the findings. We construct two idiosyncratic coskewness factors to capture the market-wide effect of idiosyncratic coskewness. The two idiosyncratic coskewness factors can also explain the negative and significant relation between the maximum daily return over the past one month (MAX) and expected stock returns documented in Bali, Cakici, and Whitelaw (2009). In addition, when we control for these two idiosyncratic coskewness factors, the return difference for distress-sorted portfolios found in Campbell, Hilscher, and Szilagyi (2008) becomes insignificant. Furthermore, the two idiosyncratic coskewness factors help us understand the idiosyncratic volatility puzzle found in Ang, Hodrick, Xing, and Zhang (2006). They reduce the return difference between portfolios with the smallest and largest idiosyncratic volatility by more than 60%, although the difference is still statistically significant., Les auteurs montrent, en modélisant des investisseurs aux préférences hétérogènes, que le rendement espéré d’actifs risqués dépend du coefficient bêta de coasymétrie idiosyncrasique, qui mesure l’évolution conjointe du rendement boursier et de la variance de chaque action. Ils observent une relation négative (positive) entre la coasymétrie idiosyncrasique et les rendements des actions lorsque le coefficient bêta de coasymétrie est positif (négatif). Les facteurs de risque usuels, comme le marché, le volume, le ratio valeur comptable-valeur de marché ou le momentum, ne permettent pas d’expliquer ce résultat. Les auteurs élaborent deux facteurs pour représenter l’incidence de la coasymétrie idiosyncrasique sur l’ensemble du marché. Ces facteurs permettent aussi d’expliquer la relation négative significative qui lie le rendement quotidien maximal enregistré pendant le mois écoulé et les rendements boursiers espérés et dont font état Bali, Cakici et Whitelaw (2009). Une fois ces facteurs idiosyncrasiques pris en compte, l’écart de rendement entre les portefeuilles de Campbell, Hilscher et Szilagyi (2008), constitués après un tri des sociétés émettrices en fonction de leur probabilité de défaut, cesse d’être significatif. Qui plus est, ces deux facteurs aident à percer l’énigme posée par la volatilité idiosyncrasique chez Ang, Hodrick, Xing et Zhang (2006). Leur inclusion réduit en effet de plus de 60 % l’écart de rendement entre les portefeuilles présentant les iv niveaux de volatilité idiosyncrasique minimal et maximal; ce dernier demeure toutefois statistiquement significatif.

The art market has seen boom and bust during the last years and, despite the downturn, has received more attention from investors given the low interest environment following the financial crisis. However, participation has been reserved for a few investors and the hedging of exposures remains dificult. This paper proposes to overcome these problems by introducing a call option on an art index, derived from one of the most comprehensive data sets of art market transactions. The option allows investors to optimize their exposure to art. For pricing purposes, non-tradability of the art index is acknowledged and option prices are derived in an equilibrium setting as well as by replication arguments. In the former, option prices depend on the attractiveness of gaining exposure to a previously non-traded risk. This setting further overcomes the problem of art market exposures being dificult to hedge. Results in the replication case are primarily driven by the ability to reduce residual hedging risk. Even if this is not entirely possible, the replication approach serves as pricing benchmark for investors who are significantly exposed to art and try to hedge their art exposure by selling a derivative. JEL Classification: G11, G13, Z11

We use a realistically calibrated life cycle model of consumption and portfolio choice to study the effects of social security on the investment decisions of households for the European case. Our model is mainly based on the one developed by Cocco, Gomes and Maenhout (2005). We extend it by unemployment risk using Markov chains to model the transition between different employment states. In contrast to most models in the life cycle literature, our model allows for three different states, namely employment, short-term as well as long-term unemployment. This allows us to examine the effects of persistence in the unemployment process on portfolio choice. Our main findings are, first, that in case of short-term unemployment only, social security systems as those established in the EU are able to offset the negative impact of unemployment risk on the portfolio-share invested in risky assets. Second, the simulation results reveal that when allowing for long-term unemployment the equity-share is suppressed, especially for young investors. We show that this negative effect of unemployment is mainly driven by its persistence.

This paper studies the effects of heterogeneity in planning propensity on wealth inequality and asset prices. I consider an economy populated by attentive and inattentive agents. Attentive agents plan their consumption period by period, while inattentive agents plan every other period. Infrequent planning increases uncertainty concerning future income or future asset returns. In general equilibrium, inattentive consumers trade at unfavorable prices. If the only source of uncertainty is future income, inattentive consumers will still accumulate more wealth. In contrast, in a version of the model driven by uncertain asset returns, infrequent planning produces the opposite result: inattentive investors accumulate less wealth, in line with empirical evidence. Moreover, asset prices are much more volatile than in a representative agent model with full attention, because changes in asset prices must induce attentive consumers to voluntarily bear the burden of adjusting to aggregate shocks.

This paper presents a simple new method for measuring `wealth effects' on aggregate consumption. The method exploits the stickiness of consumption growth (sometimes interpreted as reflecting consumption `habits') to distinguish between immediate and eventual wealth effects. In U.S. data, we estimate that the immediate (next-quarter) marginal propensity to consume from a change in housing wealth is about 2 cents, with a final eventual effect around 9 cents, substantially larger than the effect of shocks to financial wealth. We argue that our method is preferable to cointegration-based approaches, because neither theory nor evidence supports faith in the existence of a stable cointegrating vector.

We present a model for the equilibrium movement of capital between asset markets that are distinguished only by the levels of capital invested in each. Investment in that market with the greatest amount of capital earns the lowest risk premium. Intermediaries optimally trade off the costs of intermediation against fees that depend on the gain they can offer to investors for moving their capital to the market with the higher mean return. Those fees also depend on the bargaining power of the investor, in light of potential alternative intermediaries. In equilibrium, the speeds of adjustment of mean returns and of capital between the two markets are increasing in the degree to which capital is imbalanced between the two markets.

We consider the problem of portfolio selection within the classical Markowitz mean-variance framework, reformulated as a constrained least-squares regression problem. We propose to add to the objective function a penalty proportional to the sum of the absolute values of the portfolio weights. This penalty regularizes (stabilizes) the optimization problem, encourages sparse portfolios (i.e. portfolios with only few active positions), and allows to account for transaction costs. Our approach recovers as special cases the no-short-positions portfolios, but does allow for short positions in limited number. We implement this methodology on two benchmark data sets constructed by Fama and French. Using only a modest amount of training data, we construct portfolios whose out-of-sample performance, as measured by Sharpe ratio, is consistently and significantly better than that of the naive evenly-weighted portfolio which constitutes, as shown in recent literature, a very tough benchmark., Comment: Better emphasis of main result, new abstract, new examples and figures. New appendix with full details of algorithm. 17 pages, 6 figures

We provide explicit solutions to life-cycle utility maximization problems simultaneously involving dynamic decisions on investments in stocks and bonds, consumption of perishable goods, and the rental and the ownership of residential real estate. House prices, stock prices, interest rates, and the labor income of the decision-maker follow correlated stochastic processes. The preferences of the individual are of the Epstein-Zin recursive structure and depend on consumption of both perishable goods and housing services. The explicit consumption and investment strategies are simple and intuitive and are thoroughly discussed and illustrated in the paper. For a calibrated version of the model we find, among other things, that the fairly high correlation between labor income and house prices imply much larger life-cycle variations in the desired exposure to house price risks than in the exposure to the stock and bond markets. We demonstrate that the derived closed-form strategies are still very useful if the housing positions are only reset infrequently and if the investor is restricted from borrowing against future income. Our results suggest that markets for REITs or other financial contracts facilitating the hedging of house price risks will lead to non-negligible but moderate improvements of welfare.

We introduce the Homoscedastic Gamma [HG] model where the distribution of returns is characterized by its mean, variance and an independent skewness parameter under both measures. The model predicts that the spread between historical and risk-neutral volatilities is a function of the risk premium and of skewness. In fact, the equity premium is twice the ratio of the volatility spread to skewness. We measure skewness from option prices and test these predictions. We find that conditioning on skewness increases the predictive power of the volatility spread and that coefficient estimates accord with theory. In short, the data do not reject the model's implications for the equity premium. We also check the model's implications for option pricing and show that the information content of skewness leads to improved in-sample and out-of-sample pricing performances as well as improved hedging performances. Our results imply that expanding around the Gaussian density is restrictive and does not offer sufficient flexibility to match the skewness and kurtosis implicit in option data. Finally, we document the term structure of option-implied volatility, skewness and kurtosis and find that time-dependence in returns has a greater impact on skewness., Les auteurs présentent le modèle « homoscédastique gamma », ou modèle HG, où la distribution des rendements est caractérisée par sa moyenne, sa variance et un paramètre d'asymétrie. Dans le modèle HG, l'écart entre les volatilités observée et neutre à l'égard du risque est fonction de la prime de risque et du degré d'asymétrie : la prime de risque appliquée aux actions est en fait le double du ratio de l'écart de volatilité à la mesure de l'asymétrie. Les auteurs mesurent l'asymétrie à partir de prix d'options et testent la validité des prédictions de leur modèle. Ils constatent que la prise en compte de l'asymétrie a pour effet d'accroître le pouvoir prédictif de l'écart de volatilité et que les estimations des coefficients sont conformes à ce que prévoit la théorie. En bref, les données ne permettent pas de rejeter les conclusions du modèle concernant la prime relative aux actions. Les auteurs étudient aussi les implications du modèle du point de vue de l'évaluation des options. Ils montrent que le contenu informatif de la mesure de l'asymétrie permet d'améliorer la capacité de prévision du modèle, tant sur échantillon que hors échantillon, ainsi que sa performance en matière de couverture. Les résultats indiquent que le recours à une expansion au voisinage de la densité gaussienne est contraignant et n'offre pas suffisamment de souplesse pour reproduire les degrés d'asymétrie et d'aplatissement qui ressortent du prix des options. Enfin, au terme d'une analyse de la structure d'échéance de la volatilité implicite, de l'asymétrie et de l'aplatissement, les auteurs concluent que la dépendance temporelle des rendements influe davantage sur l'asymétrie.

The utility-maximizing consumption and investment strategy of an individual investor receiving an unspanned labor income stream seems impossible to find in closed form and very difficult to find using numerical solution techniques. We suggest an easy procedure for finding a specific, simple, and admissible consumption and investment strategy, which is near-optimal in the sense that the wealthequivalent loss compared to the unknown optimal strategy is very small. We first explain and implement the strategy in a simple setting with constant interest rates, a single risky asset, and an exogenously given income stream, but we also show that the success of the strategy is robust to changes in parameter values, to the introduction of stochastic interest rates, and to endogenous labor supply decisions.

I construct a behavioral model of asset pricing in which agents choose whether to base their expectations on chartist or fundamental forecasts. I simulate the model in order to test its efficacy in explaining the moments and time series properties of the FTSE All-Share index, and find that the model cannot be rejected as the data generating process.

Cahier de Recherche du Groupe HEC Paris, n° 892/2008; We consider a multi-period rational expectations model in which risk-averse investors differ in their information on past transaction prices (the ticker). Some investors (insiders) observe prices in real-time whereas other investors (outsiders) observe prices with a delay. As prices are informative about the asset payoff, insiders get a strictly larger expected utility than outsiders. Yet, information acquisition by one investor exerts a negative externality on other investors. Thus, investors' average welfare is maximal when access to price information is rationed. We show that a market for price information can implement the fraction of insiders that maximizes investors' average welfare. This market features a high price to curb excessive acquisition of ticker information. We also show that informational efficiency is greater when the dissemination of ticker information is broader and more timely.

The early work of Tobin (1958) showed that portfolio allocation decisions can be reduced to a two stage process: first decide the relative allocation of assets across the risky assets, and second decide how to divide total wealth between the risky assets and the safe asset. This so called twofund separation relies on special assumptions on either returns or preferences. Tobin (1958) analyzed portfolio demand in a mean-variance setting. We revisit the fund separation in settings that allow not only for heterogeneity of preferences for higher order moments, but also for heterogeneity of beliefs among agents. To handle the various sources of heterogeneity, beliefs, and preferences, we follow the framework of Samuelson (1970) and its recent generalization by Chabi-Yo, Leisen, and Renault (2006). This generic approach allows us to derive, for risks that are infinitely small, optimal shares of wealth invested in each security that coincide with those of a Mean-Variance-Skewness-Kurtosis optimizing agent. Besides the standard Sharpe-Lintner CAPM mutual fund separation we obtain additional mutual funds called beliefs portfolios, pertaining to heterogeneity of beliefs, a skewness portfolio similar to Kraus and Litzenberger (1976), beliefs about skewness portfolios with design quite similar to beliefs portfolios, a kurtosis portfolio, and finally portfolio heterogeneity of the preferences for skewness across investors in the economy as well as its covariation with heterogeneity of beliefs. These last two mutual funds are called cross-co-skewness portfolio and cross-co-skewness-beliefs portfolios. Under various circumstances related to return distribution characteristics, cross-agent heterogeneity and market incompleteness, some of these portfolios disappear., Dans ses premiers travaux, Tobin (1958) a montré que les décisions d'allocation d'un portefeuille peuvent se résumer en deux étapes : l'investisseur décide d'abord de la répartition des actifs au sein de la composante risquée de son portefeuille, puis de la proportion de la richesse totale à investir respectivement dans les actifs risqués et dans l'actif sans risque. Ce « théorème de séparation à deux fonds » repose sur l'adoption d'hypothèses concernant soit les rendements, soit les préférences. Tobin (1958) analysait la demande d'actifs à l'aide d'un modèle moyennevariance. Les auteurs réexaminent ici la question dans un cadre qui autorise non seulement l'hétérogénéité des préférences pour les moments d'ordre supérieur à un, mais aussi celle des croyances des investisseurs. Pour prendre en compte les diverses croyances, préférences et autres sources d'hétérogénéité existantes, ils empruntent l'approche de Samuelson (1970) ainsi que la généralisation qu'ils en ont proposée récemment dans Chabi-Yo, Leisen et Renault (2006). Leur approche générale permet d'établir, pour un niveau de risque donné, les parts optimales de la richesse qu'un agent optimisateur ayant des préférences à l'égard de l'espérance, de la variance, de l'asymétrie et de l'aplatissement de la distribution des rendements investirait dans chaque titre. Outre le portefeuille de marché classique construit à partir du modèle d'équilibre des actifs financiers de Sharpe et Lintner, les auteurs arrivent ainsi à générer : 1) différents portefeuilles qui sont fonction des croyances des investisseurs; 2) un portefeuille lié à l'asymétrie de la distribution des rendements et similaire à celui de Kraus et Litzenberger (1976); 3) des portefeuilles tributaires des croyances des agents concernant cette asymétrie et analogues aux premiers portefeuilles décrits ci-dessus; 4) un portefeuille tenant à l'aplatissement excessif de la distribution des rendements; 5) un autre associé à l'hétérogénéité des préférences à l'égard de l'asymétrie; et 6) des portefeuilles dont l'existence s'explique par la covariation de cette hétérogénéité avec celle des croyances. Dans diverses circonstances déterminées par les caractéristiques de la distribution des rendements, l'hétérogénéité des agents et l'incomplétude des marchés, certains de ces portefeuilles disparaissent.

We analyze the effects of socially responsible investment and public abatement on environmental quality and the economy in a continuous-time dynamic growth model featuring optimizing households and firms. Environmental quality is modelled as a renewable resource. Consumers can invest in government bonds or firm equity. Since investors feel partly responsible for environmental pollution when holding firm equity, they require a premium on the return to equity. We show that socially responsible investment behaviour by households partially offsets the positive effects on environmental quality of public abatement policies.

Asymmetric shocks are common in markets; securities' payoffs are not normally distributed and exhibit skewness. This paper studies the portfolio holdings of heterogeneous agents with preferences over mean, variance and skewness, and derives equilibrium prices. A three funds separation theorem holds, adding a skewness portfolio to the market portfolio; the pricing kernel depends linearly only on the market return and its squared value. Our analysis extends Harvey and Siddique's (2000) conditional mean-variance-skewness asset pricing model to non-vanishing risk-neutral market variance. The empirical relevance of this extension is documented in the context of the asymmetric GARCH-in-mean model of Bekaert and Liu (2004)., Les chocs asymétriques sont des phénomènes courants sur les marchés. La distribution des rendements des actifs financiers ne suit pas une loi normale et est asymétrique. Les auteurs étudient la composition du portefeuille d'agents hétérogènes qui ont des préférences à l'égard de la moyenne, de la variance et de l'asymétrie de la distribution des rendements, et calculent les prix d'équilibre des actifs. Ils démontrent la validité d'un théorème de séparation à trois portefeuilles, selon lequel les agents détiennent un portefeuille dont les rendements sont répartis de façon asymétrique en plus du portefeuille standard du marché; le facteur d'actualisation stochastique ne dépend linéairement que du rendement du marché et du carré de celui-ci. Les auteurs étendent le modèle d'évaluation des actifs financiers à trois moments conditionnels (moyenne, variance et asymétrie) de Harvey et Siddique (2000) pour y inclure une variance du rendement du marché neutre à l'égard du risque et toujours supérieure à zéro. Ils testent empiriquement la pertinence de cette extension au moyen du modèle GARCH-M asymétrique de Bekaert et Liu (2004).

Previous literature concludes that replacing wage taxation by taxes on a fixed factor or its rents benefits future generations. However, the effects of such steady-state gains on the transition generations have been left open. In this paper, we show that taxation of rents may also increase utility of the current generation provided tax revenues are earmarked to reduce wage taxes. In particular, a shift in the tax mix may yield an intergenerational Pareto-improvement when the initially prevailing tax mix is sufficiently skewed towards wage taxation.

This paper studies the impact of incalculable risk (i.e. ambiguity) on two alternative institutional arrangements for financial intermediation in an economy where consumers face\ud uncertain liquidity needs. \ud The ambiguity the consumers experience is modeled by their degree of confidence in their additive beliefs. The optimal liquidity allocation and two institutional arrangements for implementing this allocation are analyzed: a secondary asset market and a competitive banking sector.\ud For full confidence we obtain the well-known result that consumers prefer the deposit contract offered in the competitive banking sector over the asset market, since the former can provide the optimal cross subsidy for consumers with high liquidity needs. With increasing ambiguity this preference will be reversed: the asset market is preferred, since it avoids inefficient liquidation if the bank reserve holdings turn out to be suboptimal.

CESifo Seminar Series. Egalement paru dans : IDEI Working paper ; 298/2005; International audience; We explore the various arguments for and against the recommendation that younger households should invest a larger share of their pension wealth in risky assets. The ability of young agents to compensate their financial losses by saving more during their career provides the strongest argument in favour of younger people investing more aggressively in the stock market. Meanreversion in stock returns yields another argument. However, the uninsurability of the risky human capital goes in the opposite direction, together with the imperfect knowledge that young investors have about the distribution of asset returns.

This research addresses whether geographic diversification provides benefits over industry diversification. In the absence of constraints, no empirical evidence is found to support the argument that country diversification is superior. With short-selling constraints, however, the geographic tangency portfolio is not attainable by industry portfolios. Results with upper and lower constraints on portfolio weights as well as an out-of-sample analysis show that geographic diversification almost consistently outperforms industry portfolios, although we cannot establish statistical significance.

An economy in which deposit-taking banks of a Diamond/ Dybvig style and an asset market coexist is modelled. Firstly, within this framework we characterize distinct financial systems depending on the fraction of households with direct investment opportunities that are less efficient than those available to banks. With this fraction comparatively low, the evolving financial system can be interpreted as market-oriented. In this system, banks only provide efficient investment opportunities to households with inferior investment alternatives. Banks are not active in the secondary financial market nor do they provide any liquidity insurance to their depositors. Households participate to a large extent in the primary as well as in the secondary financial markets. In the other case of a relatively high fraction of households with inefficient direct investment opportunities, a bank-dominated financial system arises, in which banks provide liquidity transformation, are active in secondary financial markets and are the only player in primary markets, while households only participate in secondary financial markets. Secondly, we analyze the effect a run on a single bank has on the entire financial system. Interestingly, we can show that a bank run on a single bank causes contagion via the financial market neither in market-oriented nor in extremely bank-dominated financial systems. But in only moderately bank-dominated (or hybrid) financial systems fire sales of long-term financial claims by a distressed bank cause a sudden drop in asset prices that precipitates other banks into crisis. Im vorliegenden Papier wird eine Ökonomie modelliert, in der Diamond/ Dybvig- Banken neben einem Finanzmarkt koexistieren. Innerhalb dieses Ansatzes lässt sich zunächst zeigen, dass zwei sehr unterschiedliche Finanzsysteme entstehen, je nach dem wie hoch der Anteil von solchen Haushalten in der Ökonomie ist, die im Vergleich zu Banken weniger effiziente Anlagemöglichkeiten am Finanzmarkt haben. Ist der Anteil dieser Haushalte vergleichsweise gering, so entsteht ein Finanzsystem, das sich als markt-orientiertes auffassen lässt. In diesem System beschränkt sich die Funktion von Banken darauf, auch den Haushalten mit weniger rentablen Direktanlagemöglichkeiten eine effiziente Investitionsalternative zu bieten. Während hier Banken nicht am sekundären Finanzmarkt partizipieren, handeln private Haushalte sowohl am Primär- als auch am Sekundärmarkt. Einlageverträge von Banken bieten in diesem Finanzsystem keine Liquiditätsversicherung. Ist hingegen der Anteil der Haushalte mit wenig effizienten Direktanlagemöglichkeiten vergleichsweise hoch, so bildet sich eine bank-dominiertes Finanzsystem heraus, in dem Bankeinlagen sehr wohl eine Liquiditätsversicherung darstellen. In diesem Finanzsystem sind nur die Banken am Primärmarkt aktiv und partizipieren darüber hinaus auch am Sekundärmarkt. Sämtliche private Haushalte handeln hingegen nur am Sekundärmarkt. In einem zweiten Schritt wird der Effekt untersucht, der vom Zusammenbruch einer Bank auf das gesamte Finanzsystem ausgeht. Interessanterweise zeigt sich hier, dass ein Run auf eine Bank weder in einem markt-orientierten noch in einem stark bank-dominierten Finanzsystem zu Ansteckungseffekten über den Finanzmarkt führt. Nur in schwach bank-dominierten (oder hybriden) Finanzsystemen verursachen die Notverkäufe von langfristigen Finanztiteln durch eine illiquide Bank einen Preisverfall dieser Anlagen, der weitere Banken zusammenbrechen lässt.

Socially responsible investment in analyzed in a general equilibrium context. This is important in order to understand the ultimate consequences of SRI on the decisions of economic agents. Building on models by Brock (1982) and Merton (1987), SRI is modelled as the choice to voluntarily give up investment in stocks and bonds issues by a firm producing an externality. The model is used to analyze the utility costs of SRI to the responsible investor and the impact on the price of the stock issued by the firm which is responsible for the externality. The results shed light on the factors which may magnify or reduce the impact of SRI, among which are crucial the wealth commended in relative terms by the responsible agents and the diversification possibilities offered by the firms which are excluded from the investment opportunity set. A set of firms targeted by SRI may be seriously affected by SRI only if the responsible investors command a large portion of overall wealth; moreover the same firms are more likely to be hit by SRI behavior if they do not represent important diversification instruments. Firms with unique characteristics from the point of view of overall diversification are less likely to be the target of SRI.

Investor confidence is a necessary condition for the development of emerging markets. Investors recognize that since market-oriented reform policies may be reversed or hindered, they face the risk of ex post policy changes with redistributive impact on investment returns. We argue that a sustained privatization or liberalization program represents a major test of political commitment, and contributes to reduced policy risk. The evidence from our panel study suggests that progress in privatization gradually leads to increased confidence. Moreover, increased confidence has a strong effect on local market development and is a significant determinant of excess returns. We conclude that, just as financial liberalization, the resolution of policy risk resulting from successful privatization has been an important source for the broadening and deepening of emerging stock markets.

Recent empirical evidence suggests that value and momentum strategies generate significantexcess returns in emerging markets. We confirm these results and extend them in severaldirections. First, we examine a broader range of stock selection strategies, including strategiesbased on analysts' earnings revisions. We also consider multivariate strategies, whereby stocks areselected on multiple characteristics, and find that this enhances the overall performance. Excessreturns also increase if country selection is incorporated into the strategies, but the risk of thestrategies increases proportionally. Second, we test whether the strategies can be implementedsuccessfully in practice by a large institutional investor, facing a lack of liquidity, restrictions onforeign ownership and substantial transaction costs. We find that even under such more realisticcircumstances the strategies earn significant excess returns. Third, we examine several popularexplanations for the excess returns. We find no evidence of higher market risk or lower liquidity ofthe strategies. Instead, based on the developments of earnings and earnings revisions afterportfolio formation, we find that the results are consistent with behavioral explanations.

In der vorliegenden Arbeit wird ein Modell beschrieben, mit dem Ungleichverteilungen von VC untersucht werden. Im Zentrum stehen zwei Hypothesen: Die Spezialisierungshypothese, nach deren Aussage kein stattlicher Eingriff erforderlich ist, und die Hypothese der ineffizienten Ressourcenallokation, nach deren Aussage staatliches Eingreifen wünschenswert ist. Bei der Modellierung innovativer offener Volkswirtschaften werden zum einen heterogene Agenten berücksichtigt, die diskrete Entscheidungen treffen, zum anderen wird die bestehende fundamentale Unsicherheit von Innovationen eingefangen. Innovationen werden mit Eigenkapital oder Fremdkapital finanziert. Die Ersparnisse determinieren die Anzahl der Innovationen pro Periode. Durch die Unteilbarkeiten des Modells kann dieses nicht analytisch untersucht werden; die Simulationsmethode ist die adäquate Methode. Venture capital's role in technological specialisation is studied in an open economy model where the predominant mode of financing new technology-based firms (bank credits and VC) influences the economy's specialisation and growth. The model considers discrete decisions of the heterogeneous agents, adaptive expectations and fundamental uncertainty of the innovation process. A missing venture capital market can be ascribed to an inefficient allocation of resources, calling for a correction or compensation through public policy interventions or to an efficient pattern of technological specialisation based on comparative advantages of the economy, that does not justify any public intervention.

Diese Untersuchung verfolgt mehrere Ziele. Es soll ein Beitrag geleistet werden zur Klärung folgender Fragen: Welches sind die konstituierenden Merkmale von Preisblasen? Läßt sich die Existenz von Preisblasen empirisch nachweisen? Lassen sich Preisblasen von anderen typischen Phasen der Preisdynamik auf Vermögensmärkten abgrenzen? Können Preisblasen im Rahmen der gängigen Kapitalmarkttheorie erklärt werden? Lassen sich Preisblasen mit der Konzeption eines vollkommenen und effizienten Kapitalmarktes in Einklang bringen? Ist preisblasen-induzierendes Marktverhalten rational oder irrational? Welche potentiellen Ursachen von Preisblasen lassen sich identifizieren? Können Preisblasen anlagestrategisch genutzt werden?