The international diversification puzzle is not worse than you think

This paper offers two main contributions. First, it shows how the Baxter and Jermann (1997) claim that, once we consider human capital risk, the international diversification puzzle is worse than we think, is based on an econometric misspecification rejected by the data. Second, it outlines how, once the misspecification is corrected, the results are reverted: considering the human capital risk does not unequivocally worsen the puzzle and in some cases helps explaining it. JEL Classification: F30, G11, G12International diversification, human capital

Consumption Risk and the Cross-Section of Expected Returns

This paper evaluates the central insight of the Consumption Capital Asset Pricing Model (CCAPM) that an asset’s expected return is determined by its equilibrium risk to consumption. Rather than measure the risk of a portfolio by the contemporaneous covariance of its return and consumption growth — as done in the previous literature on the CCAPM and the pattern of crosssectional returns — we measure the risk of a portfolio by its ultimate consumption risk defined as the covariance of its return and consumption growth over the quarter of the return and many following quarters. While contemporaneous consumption risk explains little of the variation in observed average returns across the Fama and French 25 portfolios, ultimate consumption risk at a horizon of three years explains a large fraction of this variation.Consumption Capital Asset Pricing Model, Expected returns, Equity premium, Consumption risk, Consumption smoothing

Consumption Risk and Cross-Sectional Returns

This paper evaluates the central insight of the Consumption Capital Asset Pricing Model (C-CAPM) that an asset's expected return is determined by its equilibrium risk to consumption. Rather that measure the risk of a portfolio by the contemporaneous covariance of its return and consumption growth -- as done in the previous literature on the C-CAPM and the pattern of cross-sectional returns -- we measure the risk of a portfolio by its ultimate consumption risk defined as the covariance of its return and consumption growth over the quarter of the return and many following quarters. While contemporaneous consumption risk has little predictive power for explaining the pattern of average returns across the Fama and French (25) portfolios, ultimate consumption risk is highly statistically significant in explaining average returns and explains a large fraction of the variation in average returns. Aditionally, estimates of the average risk-free real rate of interest and the coefficient of relative risk aversion of the representative household based on ultimate consumption risk are more reasonable than those obtained using contemporaneous consumption risk.

Households’ Portfolio Diversification

This paper performs an efficiency analysis of households portfolios based on the comparison of observed portfolios with the mean-variance frontier of assets returns. Data on household portfolios are drawn from the 2001 Centro Einaudi survey, a representative sample of the Italian population with at least a bank account. We find that most households’ portfolios are extremely close to the efficient frontier once we explicitly take into account no short-selling constraints, while the null hypothesis of efficiency is rejected for all portfolios if we don’t consider these constraints.

Information asymmetries, volatility, liquidity, and the Tobin Tax

We develop a tractable model in which trade is generated by asymmetry in agents' information sets. We show that, even if news are not generated by a stochastic volatility process, in the presence of information treatment and/or order processing costs, the (unique) equilibrium price process is characterised by stochastic volatility. The intuition behind this result is simple. In the presence of trading costs and dynamic information, agents strategically choose their trading times. Since new (constant volatility) information is released to the market at trading times, the price process sampled at trading times is not characterised by stochastic volatility. But since trading and calendar times differ, the price process at calendar times is the time change of the price process at trading times – i.e. price movements on the calendar time scale are characterised by stochastic volatility. Our closed form solutions show that: i) volatility is autocorrelated and is a non-linear function of both number and volume of trades; ii) the relative informativeness of numbers and volume of trades depends on the sampling frequency of the data; iii) volatility, the limit order book, and liquidity, in terms of tightness, depth, and resilience, are jointly determined by information asymmetries and trading costs. The model is able to rationalise a large set of empirical evidence about stock market volatility, liquidity, limit order books, and market frictions, and provides a natural laboratory for analysing the equilibrium effects of a financial transaction tax

Human capital and international portfolio diversification:a reappraisal

We study the implications of human capital hedging for international portfolio choice. First, we document that, at the household level, the degree of home country bias in equity holdings is increasing in the labor income to financial wealth ratio. Second, we show that a heterogeneous agent model in which households face short selling constraints and labor income risk, calibrated to match both micro and macro labor income and asset returns data, can both rationalize this finding and generate a large aggregate home country bias in portfolio holdings. Third, we find that the empirical evidence supporting the belief that the human capital hedging motive should skew domestic portfolios toward foreign assets, is driven by an econometric misspecification rejected by the data

An information based one-factor asset pricing model

Given a set of asset returns, an information-theoretic approach is used to estimate non-parametrically the pricing kernel to price the given cross-section out-of-sample. Compared to leading factor models, this information SDF delivers smaller pricing errors and better cross-sectional fit, and identifies the maximum Sharpe ratio portfolio out-of-sample. Moreover, it extracts novel pricing information not captured by Fama-French and momentum factors, leading to an ‘information anomaly.' A tradable information portfolio that mimics this kernel has a very high out-of-sample Sharpe ratio, outperforming both the 1/N benchmark and the Value and Momentum strategies combined. These results hold for a wide cross-section of assets

The spread of COVID-19 in London: network effects and optimal lockdowns

We generalise a stochastic version of the workhorse SIR (Susceptible-Infectious- Removed) epidemiological model to account for spatial dynamics generated by network interactions. Using the London metropolitan area as a salient case study, we show that commuter network externalities account for about 42% of the propagation of COVID-19. We find that the UK lockdown measure reduced total propagation by 57%, with more than one third of the effect coming from the reduction in network externalities. Counterfactual analyses suggest that: i) the lockdown was somehow late, but further delay would have had more extreme consequences; ii) a targeted lockdown of a small number of highly connected geographic regions would have been equally effective, arguably with significantly lower economic costs; iii) targeted lockdowns based on threshold number of cases are not effective, since they fail to account for network externalities

What is the Consumption-CAPM missing? An information-theoretic framework for the analysis of asset pricing models

We study a broad class of asset pricing models in which the stochastic discount factor (SDF) can be factorized into an observable component and a potentially unobservable, model-specific, one. Exploiting this decomposition we derive new entropy bounds that restrict the admissible regions for the SDF and its components. Without using this decomposition, to a second order approximation, entropy bounds are equivalent to the canonical Hansen-Jagannathan bounds. However, bounds based on our decomposition have higher information content, are tighter, and exploit the restriction that the SDF is a positive random variable. Our information-theoretic framework also enables us to extract a non-parametric estimate of the unobservable component of the SDF. Empirically, we find it to have a business cycle pattern, and significant correlations with both financial market crashes unrelated to economy-wide contractions, and the Fama-French factors. We apply our methodology to some leading consumption-based models, gaining new insights about their empirical performance

Network risk and key players: a structural analysis of interbank liquidity

We model banks' liquidity holding decision as a simultaneous game on an interbank borrowing network. We show that at the Nash equilibrium, the contributions of each bank to the network liquidity level and liquidity risk are distinct functions of its indegree and outdegree Katz-Bonacich centrality measures. A wedge between the planner and the market equilibria arises because individual banks do not internalize the effect of their liquidity choice on other banks' liquidity benefit and risk exposure. The network can act as an absorbent or a multiplier of individual banks' shocks. Using a sterling interbank network database from January 2006 to September 2010, we estimate the model in a spatial error framework, and find evidence for a substantial, and time varying, network risk: in the period before the Lehman crisis, the network is cohesive and liquidity holding decisions are complementary and there is a large network liquidity multiplier; during the 2007-08 crisis, the network becomes less clustered and liquidity holding less dependent on the network; after the crisis, during Quantitative Easing, the network liquidity multiplier becomes negative, implying a lower network potential for generating liquidity. The network impulse-response functions indicate that the risk key players during these periods vary, and are not necessarily the largest borrowers