Consumption, the persistence of shocks, and asset price volatility

In a general equilibrium setting, a temporary component in consumption introduces a wedge between the volatility of equity returns and the volatility of consumption growth. This paper explores the asset pricing consequences of this property in a model in which consumption is the sum of a permanent and a transitory component. Permanent shocks are assumed to be rare events, while transitory shocks follow a diffusion process. When calibrated to US annual data, the model matches first and second moments of equity and bond returns for preference parameters within acceptable bounds. Permanent and transitory shocks together explain the equity premium, while transitory shocks alone explain the excess volatility of returns.     

Uninsurable risk and financial market puzzles

We compare the empirical performances of three risk-sharing arrangements involving idiosyncratic skill shocks: (a) where individuals are unable to directly insure their consumption against individual-specific shocks, (b) where agents strike long-term insurance contract with financial intermediaries involving a truth revelation constraint as in Kocherlakota and Pistaferri (2009), (c) full risk sharing. Based on the widely accepted assumption of cross-sectional log-normality of individual consumption levels, we work out closed form expressions of the pricing kernels for (a) and (b). We put these three models to test four financial market anomalies, namely the equity premium, currency premium, risk-free rate, and consumption-real exchange rate puzzles simultaneously in an integrated framework. We find that the pricing kernel associated with (a) outperforms the other two models in terms of the produced estimates of the agent’s preference parameters and the model ability to predict the equity and currency premia, the risk-free rate, and the log growth in the exchange rate. However, the predictive ability is still far from satisfactory for all three models under scrutiny.     

Can Miracles Lead to Crises? The Role of Optimism in Emerging Markets Crises

Emerging market financial crises are abrupt and dramatic usually occurring after a precrisis bonanza. This paper develops an equilibrium asset pricing model with informational frictions in which crisis itself is a  consequence  of the investor optimism in the period preceding the crisis. If preceded by a sequence of positive signals, a small, negative noise shock can trigger a downward adjustment in investors' beliefs, asset prices, and consumption. The magnitude of this downward adjustment  increases  with the level of optimism attained prior to the negative signal. Moreover, with informational frictions, asset prices display persistent effects in response to transitory shocks.     

Technological innovation and real investment booms and busts

We investigate why new, high-risk technologies can attract excessive and often unprofitable investment. We develop an equilibrium model in which rational, risk-averse agents overinvest in a risky technology, possibly to the point that its expected return is negative. Overinvestment results from relative wealth concerns which arise endogenously from the imperfect tradability of future endowments. Competition over future consumption leads to an indirect utility for wealth with “keeping up with the Joneses” properties that can induce herding. Because overinvestment increases with the risk of the technology, our model can explain why new, risky technological innovations may promote investment bubbles.     

Valuing Government Obligations When Markets Are Incomplete

We simulate a 10‐period overlapping generations model with aggregate shocks to price safe and risky government obligations using consumption‐asset pricing. Agents cannot trade with future generations to hedge the model's productivity and depreciation shocks, and can only invest in one‐period bonds and risky capital. We find that the pricing of short‐ and long‐dated riskless obligations is anchored to the prevailing risk‐free return. The prices of obligations whose values are proportional to the prevailing wage are essentially identical to those of safe obligations, notwithstanding large macro shocks. On the contrary, government obligations in the form of options entail significant risk adjustment.     

A financial CCAPM and economic inequalities

This paper considers a wealth heterogeneous multi-agent (MA) financial pricing CCAPM model. It is based on the following observations: (a) A distinction between what agents are willing to pay for consumption and what they actually pay. The former is a function of a number of factors including the agent’s wealth and risk preferences and the latter is a function of all other agents’ aggregate consumption or equivalently, their wealth committed to consumption. (b) Unlike traditional pricing models that define a representative agent underlying the pricing model, this paper assumes that each agent is in fact ‘Cournot-gaming’ a market defined by all other agents. This results in a decomposition of an n-agents game into n games of two agents, one a specific agent and the other a synthetic agent (a proxy for all other agents), on the basis of which an equilibrium consumption price solution is defined. The paper’s essential results are twofold. First, a Martingale pricing model is defined for each individual agent expressing the consumer willingness to pay (his utility price) and the market price—the price that all agents pay for consumption. In this sense, price is unique defined by each agent’s ‘Cournot game’ Agents’ consumption are then adjusted accordingly to meet the market price. Second, the pricing model defined is shown to account for agents wealth distribution pointing out that all agents valuations are a function of their and others’ wealth, the information they have about each other and other factors which are discussed in the text. When an agent has no wealth or cannot affect the market price of consumption, then this pricing model is reduced to the standard CCAPM model while any agent with an appreciable wealth compared to other agents, is shown to value returns (and thus future consumption) less than wealth-poor agents. As a result, this paper will argue that even in a financial market with an infinite number of agents, if there are some agents that are large enough to affect the market price by their decisions, such agents have an arbitrage advantage over the poorer agents. The financial CCAPM MA pricing model has a number of implications, some of which are considered in this paper. Finally, some simple examples are considered to highlight the applicability of this paper to specific financial issues.     

Liquidation equilibrium with seniority and hidden CDO

The aim of our paper is to price credit derivatives written on a single name when this name is a bank. Indeed, due to the special structure of the balance sheet of a bank and to the interconnections with other institutions of the financial system, the standard pricing formulas do not apply and their use can imply severe mispricing. The pricing of credit derivatives written on a single bank name requires a joint analysis of the risks of all banks directly or indirectly interconnected with the bank of interest. Each name cannot be priced in isolation, but the banking system must be treated as a whole. It is necessary to analyze the contagion of losses among banks, especially the equilibrium of joint defaults and recovery rates at liquidation time. We show the existence and uniqueness of such an equilibrium. Then the standard pricing formulas are modified by adding a premium to capture the contagion effects.     

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.     

The impact of keeping up with the Joneses behavior on asset prices and portfolio choice

This paper studies the asset pricing and portfolio choice implications of keeping up with the Joneses preferences. In terms of portfolio choice, we provide sufficient conditions on the utility function under which no portfolio bias can arise across agents in equilibrium. Regarding asset prices, we find that under Joneses behavior asset prices are a function of the economy's aggregate consumption, the agents preference parameters, the wealth endowment distribution and the weighting across agents in the Joneses definition. We present necessary and sufficient conditions such that equilibrium prices are only a function of aggregate wealth. Non-financial, non-diversifiable income is introduced in the model. In the presence of Joneses behavior, an under-diversified equilibrium emerges where investors will bias their portfolios towards the financial assets that better hedge their exposure to the non-financial income risk.     

Portfolio choice and mortality-contingent claims: The general HARA case

We solve a portfolio choice problem that includes mortality-contingent claims and labor income under general HARA preferences. Our contribution beyond existing literature is to (i) focus on the covariance between shocks to human capital and financial capital, to (ii) model the utility of a family with basic needs and (iii) include life insurance and pension annuity claims in one unified life-cycle model. Our solution employs a “similarity reduction” mapping which reduces the two-dimensional HJB equation into one dimension. This allows for the implementation of a quick numerical scheme. And, when shocks to human capital and financial capital are perfectly correlated, a closed-form expression is obtained as a special case.     

Pricing innovations in consumption growth: A re-evaluation of the recursive utility model

We re-evaluate the cross-sectional asset pricing implications of the recursive utility function of  and , using innovations in future consumption growth in our tests. Our empirical specification helps explain the size, value and momentum effects. Specifically, we find that (?) the beta associated with news about consumption growth has a systematic pattern: beta decreases along the size dimension and increases along the book-to-market and momentum dimensions, (??) innovation in consumption growth is significantly priced in asset returns using both the Fama and MacBeth (1973) and the stochastic discount factor approaches, and (???) the model performs better than both the CAPM and Fama–French model.     

Financial contagion and the role of the central bank

We investigate the role of a central bank (CB) in preventing and avoiding financial contagion. The CB, by imposing reserve requirements on the banking system, trades off the cost of reducing the resources available for long-term investment with the benefit of raising liquidity to face an adverse shock that could cause contagious crises. We argue that contagion is not due to the structure of the interbank deposit market, but to the impossibility to sign contracts contingent on unforeseen contingencies. As long as incomplete contracts are present, the CB may have a useful role in curbing contagion. Moreover, the CB allows the banking system to reach first-best allocation in all the states of the world when the notion of incentive-efficiency is considered. If the analysis is restricted to constrained-efficiency, the CB still avoids contagion without, however, reaching first-best consumption allocation. The model provides a rationale for reserve requirements without the presence of fiat money or asymmetric information.     

Asset pricing with heterogeneous beliefs and relative performance

We propose an equilibrium asset pricing model in which agents with heterogeneous beliefs care about relative performance. We find that the concern with relative performance leads agents to trade more similarly, a development that has two effects. First, similar trading directly decreases volatility. Second, similar trading decreases the impact of dominant agents. The second effect dominates the first when agents expect large differences between their final performances, and vice versa when agents expect small differences between their final performances. Compared with the case in which agents are unconcerned about relative performance, the stock return volatility is higher when the second effect dominates, and lower when the first effect dominates. This paper also demonstrates that the concern about relative performance influences investors’ holdings, stock prices and risk premia.     

Consumption and Hedging in Oil‐Importing Developing Countries

We study the consumption and hedging strategy of an oil‐importing developing country that faces multiple crude oil shocks. In our model, developing countries have two particular characteristics: their economies are mainly driven by natural resources and their technologies are less efficient in energy usage. The natural resource exports can be correlated with the crude oil shocks. The country can hedge against the crude oil uncertainty by taking long/short positions in existing crude oil futures contracts. We find that both inefficiencies in energy usage and shocks to the crude oil price lower the productivity of capital. This generates a negative income effect and a positive substitution effect, because today’s consumption is relatively cheaper than tomorrow’s consumption. Optimal consumption of the country depends on the magnitudes of these effects and on its risk‐aversion degree. Shocks to other crude oil factors, such as the convenience yield, are also studied. We find that the persistence of the shocks magnifies the income and substitution effects on consumption, thus also affecting the hedging strategy of the country. The demand for futures contracts is decomposed in a myopic demand, a pure hedging term and productive hedging demands. These hedging demands arise to hedge against changes in the productivity of capital due to changes in crude oil spot prices. We calibrate the model for Chile and study to what extent the country’s copper exports can be used to hedge the crude oil risk.     

Deposit insurance, bank regulation, and financial system risks

Empirical evidence is presented to show that in modern times banks can hedge liquidity shocks but could not do so prior to FDIC insurance. However, the government's limitations in properly pricing FDIC insurance are leading to many current examples of moral hazard. A model is presented to show that if insurance premiums are set to be “actuarially fair,” incentives for banks to take excessive systematic risks remain. Motivated by empirical evidence that money market mutual funds also can hedge liquidity shocks, I consider an alternative government insurance system that mitigates distortions to risk-taking yet preserves liquidity hedging and information synergies.     

International risk sharing is better than you think, or exchange rates are too smooth

Exchange rates depreciate by the difference between domestic and foreign marginal utility growth or discount factors. Exchange rates vary a lot, as much as 15% per year. However, equity premia imply that marginal utility growth varies much more, by at least 50% per year. Therefore, marginal utility growth must be highly correlated across countries: international risk sharing is better than you think. Conversely, if risks really are not shared internationally, exchange rates should vary more than they do: exchange rates are too smooth. We calculate an index of international risk sharing that formalizes this intuition. We treat carefully the realistic case of incomplete capital markets. We contrast our estimates with the poor risk sharing suggested by consumption data and home-bias portfolio calculations.     

Incomplete markets, labor supply and capital accumulation

Endogenous labor supply decisions are introduced in an equilibrium model of limited insurance against idiosyncratic shocks. Unlike in the standard case with exogenous labor (e.g. [Aiyagari, S.R., 1994. Uninsured idiosyncratic risk and aggregate saving. Quarterly Journal of Economics 109, 659-684; Huggett, M., 1997. The one-sector growth model with idiosyncratic shocks: steady states and dynamics. Journal of Monetary Economics 39, 385-403]), labor supply is likely to be lower than under complete markets. This is due to an ex post wealth effect on labor supply (rich productive agents work fewer hours) that runs counter the precautionary savings motive. As a result, equilibrium savings and output may be lower under incomplete markets. It is also found that long-run savings remain finite even when the interest rate equals the inverse of the discount factor.     

Optimal multi-period consumption and investment with short-sale constraints

This article examines agents’ consumption-investment problem in a multi-period pure exchange economy where agents are constrained with the short-sale of state-dependent risky contingent claims. In equilibrum, agents hold options written on aggregate consumption in their optimal portfolios. Furthermore, under the specific case of quadratic utility, the optimal risk-sharing rule derived for the pricing agent leads to a multifactor conditional consumption-based capital asset pricing model (CCAPM), where excess option returns appear as factors.     

Competitive risk sharing contracts with one-sided commitment

This paper analyzes dynamic equilibrium risk sharing contracts between profit-maximizing intermediaries and a large pool of ex ante identical agents that face idiosyncratic income uncertainty that makes them heterogeneous ex post. In any given period, after having observed her income, the agent can walk away from the contract, while the intermediary cannot, i.e. there is one-sided commitment. We consider the extreme scenario that the agents face no costs to walking away, and can sign up with any competing intermediary without any reputational losses. We demonstrate that not only autarky, but also partial and full insurance can obtain, depending on the relative patience of agents and financial intermediaries. Insurance can be provided because in an equilibrium contract an up-front payment effectively locks in the agent with an intermediary. We then show that our contract economy is equivalent to a consumption-savings economy with one-period Arrow securities and a short-sale constraint, similar to Bulow and Rogoff [1989. Sovereign debt: is to forgive to forget? American Economic Review 79, 43-50]. From this equivalence and our characterization of dynamic contracts it immediately follows that without cost of switching financial intermediaries debt contracts are not sustainable, even though a risk allocation superior to autarky can be achieved.