Homeownership as a Constraint on Asset Allocation

Personal preferences and financial incentives make homeownership desirable for most families. Once a family purchases a home they find it impractical (costly) to frequently change their ownership of residential real estate. Thus, by deciding how much home to buy, a family constrains their ability to adjust their asset allocation between residential real estate and other assets. To analyze the impact of this constraint on consumption, welfare, and post-retirement wealth, we first investigate an individual’s optimal asset allocation decisions when they are subject to a “homeownership constraint.” Next, we perform a “thought experiment” where we assume the existence of a market where a homeowner can sell, without cost, a fractional interest in their home. Now the housing choice decision does not constrain the individual’s asset allocations. By comparing these two cases, we estimate the differences in post-retirement wealth and the welfare gains potentially realizable if asset allocations were not subject to a homeownership constraint. For realistic parameter values, we find that the homeowner would require a substantial increase in total net worth to achieve the same level of utility as would be achievable if the choice of a home could be separated from the asset allocation decision. The robustness of the analysis is evaluated with respect to the model’s parameters and initial state variables. We find that changes in the values of the constraint (i.e., the value of the home) and the expected real rate of home value appreciation are the only state variables or parameter that is associated with a large change in asset allocation and/or the burden imposed by the housing constraint. This finding suggests the importance of a detailed examination of the impact of inter-regional differences in home prices and expected rates of appreciation on asset allocation and post-retirement wealth.     

Transfer pricing in vertically integrated industries

Tax officials judge whether a multinational’s transfer price is consistent with the arm’s-length standard, the price at which two independent firms would carry out a similar transaction, by using data from comparable but independent transactions. In vertically integrated industries, the only source of comparable data may be from controlled (nonindependent) transactions. Conventional wisdom asserts that standard arm’s-length methods cannot perform well in such markets because the comparability rules encourage the integrated firms to collude tacitly on transfer prices in a way that amplifies tax-differential incentives. In this paper, we show that strategic linkages between vertically integrated firms operating in the same final good market moderate, and can possibly reverse, tax-differential incentives if the correct comparison method is used. The Cost-Plus method turns out to be the most effective in limiting the equilibrium amount of profit-shifting out of the high-tax country and it yields the highest tax revenues for the high-tax country. These benefits are shown to strengthen when the firms have private cost information.      

Partial equilibria with convex capital requirements: existence,uniqueness and stability

We consider several risk-averse financial agents who negotiate the price of a bundle of contingent claims in an incomplete semimartingale model of a financial market. Assuming that the agents’ risk preferences are modeled by convex capital requirements, we define and analyze their demand functions and propose a notion of a partial equilibrium price. In addition to sufficient conditions for the existence and uniqueness, we also show that the equilibrium prices are stable with respect to misspecifications of agents’ risk preferences.     

The numéraire portfolio in semimartingale financial models

We study the existence of the numéraire portfolio under predictable convex constraints in a general semimartingale model of a financial market. The numéraire portfolio generates a wealth process, with respect to which the relative wealth processes of all other portfolios are supermartingales. Necessary and sufficient conditions for the existence of the numéraire portfolio are obtained in terms of the triplet of predictable characteristics of the asset price process. This characterization is then used to obtain further necessary and sufficient conditions, in terms of a no-free-lunch-type notion. In particular, the full strength of the “No Free Lunch with Vanishing Risk” (NFLVR) condition is not needed, only the weaker “No Unbounded Profit with Bounded Risk” (NUPBR) condition that involves the boundedness in probability of the terminal values of wealth processes. We show that this notion is the minimal a-priori assumption required in order to proceed with utility optimization. The fact that it is expressed entirely in terms of predictable characteristics makes it easy to check, something that the stronger NFLVR condition lacks.      

Prospect theory and the risk-return paradox: some recent evidence

There is extensive evidence indicating a negative risk–return relation when a firm’s performance is measured based on accounting measures such as return on asset (ROA) and return on equity (ROE). Previous studies show that the risk-return paradox can be explained by the prospect theory, which predicts that managers’ risk attitudes are different for firms of different performances. However, those studies mostly use earlier data from the COMPUSTAT database, which suffers from a survivorship bias. Failure to account for delisting firms may understate the risk–return relation. We reexamine the mixture of risk-seeking and risk-averse behaviors based on an updated 20-year sample period that is free from the survivorship problem. Interestingly, our results show stronger and robust evidence supporting the prospect theory during the period from 1984 to 2003.     

Property Segment and REIT Capital Structure

This paper relies on an increasing number of industry equilibrium studies linking a firm to its industry peers to help explain the observed REIT capital structure variation within property segments beyond what is possible with the traditional partial equilibrium trade-off and pecking order theories, which assume that each firm operates in isolation from other market participants and are not particularly suitable to REITs because of the regulated setting within which these firms operate. We build several proxies for a REIT’s position within its property segment. Consistent with the competitive equilibrium model of Maksimovic and Zechner (1991), we find that a REIT’s volatility of operating performance relative to the median volatility of operating performance of its segment peers is an important determinant of its leverage ratio. We also find that a REIT’s leverage ratio depends on the median leverage ratio in its segment. Leverage is also related to a REIT’s status as an incumbent and its role as a leader in the property segment.     

Stability of marketable payoffs with long-term assets

We consider a stochastic financial exchange economy with a finite date-event tree representing time and uncertainty and a financial structure with possibly long-term assets. We exhibit a sufficient condition under which the set of marketable payoffs depends continuously on the arbitrage free asset prices. This generalizes previous results of Angeloni–Cornet and Magill–Quinzii involving only short-term assets. We also show that, under the same condition, the useless portfolios do not depend on the arbitrage free asset prices. We then provide an existence result of financial equilibrium for long term nominal assets for any given state prices with assumptions only on the fundamental datas of the economy.     

Information reduction via level crossings in a credit risk model

This paper provides an alternative credit risk model based on information reduction where the market only observes the firm’s asset value when it crosses certain levels, interpreted as changes significant enough for the firm’s management to make a public announcement. For a class of diffusion processes we are able to provide explicit expressions for the firm’s default intensity process and its zero-coupon bond prices.      

An example of a stochastic equilibrium with incomplete markets

We prove existence and uniqueness of stochastic equilibria in a class of incomplete continuous-time financial environments where the market participants are exponential utility maximizers with heterogeneous risk-aversion coefficients and general Markovian random endowments. The incompleteness featured in our setting—the source of which can be thought of as a credit event or a catastrophe—is genuine in the sense that not only the prices, but also the family of replicable claims itself are determined as a part of the equilibrium. Consequently, equilibrium allocations are not necessarily Pareto optimal and the related representative-agent techniques cannot be used. Instead, we follow a novel route based on new stability results for a class of semilinear partial differential equations related to the Hamilton–Jacobi–Bellman equation for the agents’ utility maximization problems. This approach leads to a reformulation of the problem where the Banach fixed-point theorem can be used not only to show existence and uniqueness, but also to provide a simple and efficient numerical procedure for its computation.     

First steps towards an equilibrium theory for Lévy financial markets

For a continuous-time financial market with a single agent, we establish equilibrium pricing formulae under the assumption that the dividends follow an exponential Lévy process. The agent is allowed to consume a lump at the terminal date; before that, only flow consumption is allowed. The agent’s utility function is assumed to be additive, defined via strictly increasing, strictly concave smooth felicity functions which are bounded below (thus, many CRRA and CARA utility functions are included). For technical reasons we require for our equilibrium existence result that only pathwise continuous trading strategies are permitted in the demand set. The resulting equilibrium asset price processes depend on the agent’s risk aversion (through the felicity functions). Even in our simple, straightforward economy, the equilibrium asset price processes will essentially only be (stochastic) exponential Lévy processes when they are already geometric Brownian motions. Our equilibrium asset pricing formulae can also be modified to obtain explicit equilibrium derivative pricing formulae.     

On equilibrium asset price processes

In this article we derive necessary and sufficient conditionsthat must be satisfied by equilibrium asset price processesin a pure exchange economy. We examine a world in which assetprices follow a diffusion process, asset markets are dynamicallycomplete, all investors maximize their (state-independent) expectedutility of consumption at some future date, and investors havenonrandom exogenous income. We show that it is necessary andsufficient that the coefficients of an equilibrium diffusionprice process satisfy a partial differential equation and aboundary condition. We also examine how the dynamics of assetprices are related to the shape of the representative investor'sutility function through the boundary condition. For example,in a constant-volatility economy, the expected instantaneousreturn of the market portfolio is mean reverting if and onlyif the relative risk aversion of the representative investoris decreasing in terminal wealth.     

On Ponzi schemes in infinite horizon collateralized economies with default penalties

We show, by means of an example, that in models where default is subject to both collateral repossession and utility punishments, opportunities for doing Ponzi schemes are not always ruled out and (refined) equilibria may fail to exist. This is true even if default penalties are moderate as defined in Páscoa and Seghir (Game Econ Behav 65:270–286, 2009). In our example, asset promises and default penalties are chosen such that, if an equilibrium does exist, agents never default on their promises. At the same time collateral bundles and utility functions are such that the full repayment of debts implies that the asset price should be strictly larger than the cost of collateral requirements. This is sufficient to induce agents to run Ponzi schemes and destroy equilibrium existence.     

Foreign currency bubbles

This paper develops a new model for studying foreign currency exchange rate bubbles. The model constructed is a modification of the martingale based bubble approach of Jarrow et al. (Adv Math Finance 105–130, 2006; Math Finance 20(2):145–185, 2008). This model generates some new insights into our understanding of exchange rate bubbles and it can be utilized empirically to test for their existence. The new insights are: (1) exchange rate bubbles can be negative, in contrast to asset price bubbles, (2) exchange rate bubbles are caused by price level bubbles in either or both of the relevant countries’ currencies, and (3) price level bubbles decrease the expected inflation rate in the domestic economy.     

A note on asset management and market risk

The textbook view on risk in asset management companies is summarized by Hull (Risk Management and Financial Institutions, p. 372, 2007): “For an asset manager the greatest risk is operational risk.” Using evidence from various panel regression models, we show that asset management revenues carry substantial market risks, a finding that challenges not only academic risk management literature on the predominance of operative risks, but also the current industry practice of not hedging market risks that are systematically built into the revenue-generation process. For asset management companies to return to an annuity model, these risks need to be managed more actively. Shareholders do not want to be exposed to market beta by investing in asset management companies; they want to participate in these companies’ alpha generation and take advantage of their fund-gathering expertise as financial intermediaries.     

Return predictability and shareholders’ real options

This study re-interprets the properties of the residual income model by highlighting the shareholders’ abandonment (liquidation or adaptation) option. We estimate the value of this real option as an explicit component of abnormal earnings in the residual income model and test the improvement in valuation after incorporating it into the model. Relative to the traditional specification of the residual income model, this real options model has a stronger predictive power for future abnormal stock returns. We also find that the superior return predictability of the real options model is pronounced in the set of firms with a high probability of exercising liquidation options (for example, those with low profitability, low growth opportunities, high underlying asset volatility, and low intangible assets), which is consistent with the importance of shareholders’ abandonment option in equity valuation. The results are robust to extensive sensitivity checks.     

Asset price bubbles from heterogeneous beliefs about mean reversion rates

Harrison and Kreps showed in 1978 how the heterogeneity of investor beliefs can drive speculation, leading the price of an asset to exceed its intrinsic value. By focusing on an extremely simple market model—a finite-state Markov chain—the analysis of Harrison and Kreps achieved great clarity but limited realism. Here we achieve similar clarity with greater realism, by considering an asset whose dividend rate is a mean-reverting stochastic process. Our investors agree on the volatility, but have different beliefs about the mean reversion rate. We determine the minimum equilibrium price explicitly; in addition, we characterize it as the unique classical solution of a certain linear differential equation. Our example shows, in a simple and transparent manner, how heterogeneous beliefs about the mean reversion rate can lead to everlasting speculation and a permanent “price bubble.”     

Dynamic programming and mean-variance hedging with partial execution risk

In this paper I consider a hedging problem in an illiquid market where there is a risk that the hedger’s order to buy or sell the underlying asset may be executed only partially. In this setting, I find a mean-variance optimal hedging strategy by the dynamic programming method. The solution contains a new endogenous state variable representing the current position in the underlying. The exogenous coefficients in the solution are given by recursive formulas which can be calculated efficiently in Markov models. I illustrate effects of the partial execution risk in several examples.      

Risk management using index-linked catastrophic loss instruments

One way for insurance companies to ensure against high losses due to catastrophic events is the purchase of index-based catastrophic loss instruments. The payoff of these instruments is strongly related to the development of an index, which implies that the degree and type of dependence between the insurer’s losses and the index is crucial for their hedging effectiveness. In addition, management strategies on the asset side play an important role for risk management. In this paper, effects of investment decisions and index-based risk transfer instruments on an insurer’s solvency capital requirements are investigated with special focus on the impact of the degree and type of dependence between relevant processes.     

The price of rapid exit in venture capital-backed IPOs

This paper proposes an explanation for two empirical puzzles surrounding initial public offerings (IPOs). Firstly, it is well documented that IPO underpricing increases during “hot issue” periods. Secondly, venture capital (VC) backed IPOs are less underpriced than non-venture capital backed IPOs during normal periods of activity, but the reverse is true during hot issue periods: VC backed IPOs are more underpriced than non-VC backed ones. This paper shows that when IPOs are driven by the initial investor’s desire to exit from an existing investment in order to finance a new venture, both the value of the new venture and the value of the existing firm to be sold in the IPO drive the investor’s choice of price and fraction of shares sold in the IPO. When this is the case, the availability of attractive new ventures increases equilibrium underpricing, which is what we observe during hot issue periods. Moreover, I show that underpricing is affected by the severity of the moral hazard problem between an investor and the firm’s manager. In the presence of a moral hazard problem the degree of equilibrium underpricing is more sensitive to changes in the value of the new venture. This can explain why venture capitalists, who often finance firms with more severe moral hazard problems, underprice IPOs less in normal periods, but underprice more strongly during hot issue periods. Further empirical implications relating the fraction of shares sold and the degree of underpricing are presented.      

Volatilities and Momentum Returns in Real Estate Investment Trusts

We examine the relation of time-varying idiosyncratic risk and momentum returns in REITs using a GARCH-in-mean model and incorporate liquidity risk in the asset pricing model. This is important because illiquidity may be more severe for REITs due to the nature of their underlying assets. We find that momentum returns display asymmetric volatility, i.e., momentum returns are higher when volatility is higher. Additionally, we find evidence that REITs with lowest past returns (losers) have higher idiosyncratic risks than those with highest past returns (winners) and that investors require a lower risk premium for holding losers’ idiosyncratic risks. Therefore, although losers have higher levels of idiosyncratic risks, their low risk premia cause low returns, which contribute to momentum. Lastly, we find a positive relation between REITs’ momentum return and turnover.