Suleyman Basak

A model of dynamic equilibrium asset pricing with heterogeneous beliefs and extraneous risk

Abstract We study equilibrium security price dynamics in an economy where nonfundamental risk arises from agents’ heterogeneous beliefs about extraneous processes. We completely characterize equilibrium in terms of the economic primitives, via a representative agent with stochastic weights. Besides pricing fundamental risk, an agent now also prices nonfundamental risk with a market price which is a risk-tolerance weighted average of his extraneous disagreement with all remaining agents. Consequently, agents’ perceived state prices and consumption are more volatile in the presence of extraneous risk. The interest rate inherits additional terms from: agents’ misperceptions about consumption growth, and precautionary savings motives against the nonfundamental uncertainty.

Asset Prices and Institutional Investors

Empirical evidence indicates that trades by institutional investors have sizable effects on asset prices, generating phenomena such as index effects, asset-class effects and others. It is difficult to explain such phenomena within standard representative-agent asset pricing models. In this paper, we consider an economy populated by institutional investors alongside standard retail investors. Institutions care about their performance relative to a certain index. Our framework is tractable, admitting exact closed-form expressions, and produces the following analytical results. We find that institutions optimally tilt their portfolios towards stocks that comprise their benchmark index. The resulting price pressure boosts index stocks, while leaving nonindex stocks unaffected. By demanding a higher fraction of risky stocks than retail investors, institutions amplify the index stock volatilities and aggregate stock market volatility, and give rise to countercyclical Sharpe ratios. Trades by institutions induce excess correlations among stocks that belong to their benchmark index, generating an asset-class effect.

A Model of Financialization of Commodities

A sharp increase in the popularity of commodity investing in the past decade has triggered an unprecedented inflow of institutional funds into commodity futures markets, referred to as the financialization of commodities. In this paper, we explore the effects of financialization in a model that features institutional investors alongside traditional futures markets participants. The institutional investors care about their performance relative to a commodity index. We find that in the presence of institutional investors prices and volatilities of all commodity futures go up, but more so for the index futures than for nonindex ones. The correlations amongst commodity futures as well as in equity-commodity correlations also increase, with higher increases for index commodities. Within a framework additionally incorporating storage, we show how financial markets transmit shocks not only to futures prices but also to commodity spot prices and inventories. Commodity spot prices and inventories go up with financialization. In the presence of institutional investors shocks to any index commodity spill over to all storable commodity prices.

Risk Management with Benchmarking

Portfolio theory must address the fact that, in reality, portfolio managers are evaluated relative to a benchmark, and therefore adopt risk management practices to account for the benchmark performance. We capture this risk management consideration by allowing a prespecified shortfall from a target benchmark-linked return, consistent with growing interest in such practice. In a dynamic setting, we demonstrate how a risk-averse portfolio manager optimally under- or overperforms a target benchmark under different economic conditions, depending on his attitude towards risk and choice of the benchmark. The analysis therefore illustrates how investors can achieve their desired performance profile for funds under management through an appropriate combined choice of the benchmark and money manager. We consider a variety of extensions, and also highlight the ability of our setting to shed some light on documented return patterns across segments of the money management industry.

An Intertemporal Model of International Capital Market Segmentation

This paper develops an intertemporal model of international capital market segmentation. Within the model, under various forms of segmentation/integration, the equilibrium asset prices and allocations, the risk-free interest rate, and the intertemporal consumption behavior and welfares of two countries are derived and compared. It is shown that the equilibrium interest rate is increased on integration, and that integrating markets may be significantly welfare decreasing for one of the countries. Conditions that may lead to a decrease in welfare are investigated. The conclusions as to the effects of segmentation on asset prices in the mean-variance model of the existing finance segmentation literature are also shown to break down in an intertemporal model.

Currency Prices, the Nominal Exchange Rate, and Security Prices in a Two Country Dynamic Monetary Equilibrium

This paper examines a continuous-time two country dynamic monetary equilibrium in which countries with possible heterogeneous tastes and endowments hold their own money for the purpose of transaction services formulated via the money in the utility function. Given a price system, no-arbitrage pricing results are provided for the price of each money and the nominal exchange rate. Characterizations are provided for equilibrium prices for general time-additive preferences and non-Markovian exogenous processes.

Difference in Interim Performance and Risk Taking with Short-Sale Constraints

Absent much theory, empirical works often rely on the following informal reasoning when looking for evidence of a mutual fund tournament: If there is a tournament, interim winners have incentives to decrease their portfolio volatility as they attempt to protect their lead, while interim losers are expected to increase their volatility so as to catch up with winners. We consider a rational model of a mutual fund tournament in the presence of short-sale constraints and find the opposite: Interim winners choose more volatile portfolios in equilibrium than interim losers. Several empirical works present evidence consistent with our model. However, based on the above informal argument, they appear to conclude against the tournament behavior. We argue that this conclusion is unwarranted. We also demonstrate that tournament incentives lead to differences in interim performance for otherwise identical managers and that mid-year trading volume is inversely related to mid-year stock return.

Multiplicity in General Financial Equilibrium with Portfolio Constraints

This paper explores the role of portfolio constraints in generating multiplicity of equilibrium. We present a simple financial market economy with two goods and two households, households who face constraints on their ability to take unbounded positions in risky stocks. Absent such constraints, equilibrium allocation is unique and is Pareto efficient. With one portfolio constraint in place, the efficient equilibrium is still possible; however, additional inefficient equilibria in which the constraint is binding may emerge. We show further that with portfolio constraints cum incomplete markets, there may be a continuum of equilibria; adding incomplete markets may lead to real indeterminacy.

International Good Market Segmentation and Financial Innovation

While financial markets have recently become more complete and international capital flows well liberalized, markets for goods remain segmented. To investigate how financial innovation and more complete security markets may relieve the effects of this segmentation, we examine a series of two-country economies with internationally segmented good markets, distinguished by the available financial securities. We show that risk-sharing may be limited even with complete financial markets, and that additional securities may be needed to reach an efficient equilibrium allocation; the location of these securities also profoundly affects the equilibrium. Key to this result is our assumption that there may be heterogeneity and imperfect risk-sharing within countries as well as across countries, a novelty of this work. Sufficient conditions for efficiency include complete international financial markets together with liberalized international financial flows. Under these conditions, heterogeneous agents from the same country may use securities as a substitute for the international shipment of goods. This allows them to partially circumvent the segmentation, allowing for efficient risk sharing.

Belief Dispersion in the Stock Market

We develop a dynamic model of belief dispersion with a continuum of investors differing in beliefs. The model is tractable and qualitatively matches many of the empirical regularities in a stock price, its mean return, volatility, and trading volume. We find that the stock price is convex in cash-flow news and increases in belief dispersion, while its mean return decreases when the view on the stock is optimistic, and vice versa when pessimistic. Moreover, belief dispersion leads to a higher stock volatility and trading volume. We demonstrate that otherwise identical two-investor heterogeneous-beliefs economies do not necessarily generate our main results.