How important is intra-household risk sharing for savings and labor supply?

While it is recognized that the family is a risk-sharing institution, little is known about the quantitative effects of this source of insurance on savings and labor supply. In this paper, we present a model where workers (females and males) are subject to idiosyncratic employment risk and where capital markets are incomplete. A household is formed by a female and a male, who decide on consumption, savings and labor supplies. In a calibrated version of our model we find that intra-household risk sharing has its largest impact among wealth-poor households. While the wealth-rich use mainly savings to smooth consumption across unemployment spells, wealth-poor households rely on spousal labor supply. For instance, for low-wealth households, average hours worked by wives of unemployed husbands are 8% higher than those worked by wives of employed husbands. This response in wives’ hours makes up 9% of lost family income. We also study consumption losses upon an unemployment spell, precautionary savings and the crowding out effects of the public unemployment insurance program on the extent of risk sharing within the household.     

Understanding European unemployment with a representative family model

A representative family model with indivisible labor and employment lotteries has no labor market frictions and complete markets. Nevertheless, its aggregate responses to an increase in government supplied unemployment insurance (UI) and to an increase in microeconomic turbulence are qualitatively similar to those in two macromodels with labor market frictions and incomplete markets, namely, the matching and search-island models in Ljungqvist and Sargent [2007a. Understanding European unemployment with matching and search-island models. Journal of Monetary Economics, this issue]. Because there is no frictional unemployment in the representative family model, an increase in employment protection (EP) decreases aggregate work because the representative family substitutes leisure for work, an effect opposite to what occurs in matching and search-island models. Heterogeneity among workers highlights the economy-wide coordination in labor supply and consumption sharing that employment lotteries and complete markets achieve in the representative family model. A high disutility of labor makes generous UI cause very low employment levels.     

Idiosyncratic production risk, growth and the business cycle

We introduce a neoclassical growth economy with idiosyncratic production risk and incomplete markets. Each agent is an entrepreneur operating her own technology with her own capital stock. The general equilibrium is characterized by a closed-form recursion in the CARA-normal case. Incomplete markets introduce a risk premium on private equity, which reduces the demand for investment. As compared to complete markets, the steady state can thus have both a lower capital stock due to investment risk, and a lower interest rate due to precautionary savings. Furthermore, the anticipation of high real interest rates in the future feeds back into high risk premia and low investment in the present, thus slowing down convergence to the steady state. Our results highlight the importance of private risk premia for capital accumulation and business cycles.     

The strategic specialist and imperfect competition in a limit order market

The empirical literature suggests that the limit order book contains information that might be used by the specialist to his own advantage. I develop a model where there is a strategic specialist who competes against a limit order book and has information about supply. The presence of a strategic specialist in an imperfectly competitive limit order book market induces non-monotonicity of market indicators with respect to the variance of liquidation value. Moreover, the existence of private information about supply significantly affects market performance as it induces, among other effects, lower market liquidity. Finally, this model suggests another link between Kyle’s (1985, 1989) [Kyle, A., 1985. Continuous auctions and insider trading. Econometrica 53, 1315–1336, Kyle, A., 1989. Informed speculators with imperfect competition. Review of Economic Studies 56, 317–356] and Glosten and Milgrom’s (1985) [Glosten, L., Milgrom, P., 1985. Bid, ask and transaction prices in a specialist market with heterogeneously informed markets. Journal of Financial Economics 14, 71–100] models by allowing for strategic behaviour of the specialist.     

Comment on: “Estimating the expected marginal rate of substitution”

The methodology proposed in Flood and Rose [2005. Estimating the expected marginal rate of substitution: a systematic exploration of idiosyncratic risk. Journal of Monetary Economics 52 (5) 951-969] fails to distinguish between the single unique marginal rate of substitution (MRS) process and the class of valid pricing kernels, of which the MRS is but a particular member. Thus, at best, this methodology explores the properties of some arbitrary pricing kernel, which may differ radically from the true MRS. Furthermore, the estimates of the expected MRS proposed by Flood and Rose [2005. Estimating the expected marginal rate of substitution: a systematic exploration of idiosyncratic risk. Journal of Monetary Economics 52 (5) 951-969] are highly correlated with ex post shocks, implying that these estimates are not conditional expectations at all. The cure for this misspecification introduces additional econometric problems, suggesting that the model may, in practice, be poorly identified.     

Insurance and opportunities: A welfare analysis of labor market risk

Using a model with constant relative risk-aversion preferences, endogenous labor supply and partial insurance against idiosyncratic wage risk, this paper provides an analytical characterization of three welfare effects: (a) the welfare effect of a rise in wage dispersion, (b) the welfare gain from completing markets, and (c) the welfare effect from eliminating risk. The analysis reveals an important trade-off for these welfare calculations. On the one hand, higher wage uncertainty increases the cost associated with missing insurance markets. On the other hand, greater wage dispersion presents opportunities to raise aggregate productivity by concentrating market work among more productive workers. Welfare effects can be expressed in terms of the underlying parameters defining preferences and wage risk or, alternatively, in terms of changes in observable second moments of the joint distribution over individual wages, consumption and hours.     

市场摩擦对特质风险溢价的影响效应——基于A股主板市场的实证分析

与国外发达市场相比,我国A股主板市场的市场摩擦因素对市场微观结构和资产定价的影响更大。在防范和化解系统性风险的过程中,进一步分析市场摩擦如何作用于特质风险定价效应的问题具有重要的理论和现实意义。本文通过采用多维市场摩擦指标来代理信息不对称、交易成本、买卖限制、卖空限制、风险对冲和外部冲击,检验中国股市特质风险和预期收益率的关系,并判断出市场摩擦因素间的差异性影响机制。回归发现,市场摩擦和特质风险因子(特质波动率和特质偏度)都具有定价效应。各维度市场摩擦因素降低了股票流动性,进而增强了特质波动率的负向定价效应,部分解释了“特质波动率之谜”,但市场摩擦对特质偏度因子溢价的影响较为微弱。同时,基于特质波动率和特质偏度因子的投资策略能够产生超越CAPM、三因子和五因子模型的绝对收益,并印证了市场摩擦对特质风险因子绝对收益的影响作用。     

Market liquidity, asset prices, and welfare

This paper represents an equilibrium model for the demand and supply of liquidity and its impact on asset prices and welfare. We show that, when constant market presence is costly, purely idiosyncratic shocks lead to endogenous demand of liquidity and large price deviations from fundamentals. Moreover, market forces fail to lead to efficient supply of liquidity, which calls for potential policy interventions. However, we demonstrate that different policy tools can yield different efficiency consequences. For example, lowering the cost of supplying liquidity on the spot (e.g., through direct injection of liquidity or relaxation of ex post margin constraints) can decrease welfare while forcing more liquidity supply (e.g., through coordination of market participants) can improve welfare.     

Securitized markets,international capital flows,and global welfare

We study the effect of collateralized lending and securitization on international capital flows and welfare in a two-country general equilibrium model with idiosyncratic investment risk. The low-margin country (Home) endogenously supplies more safe assets and enables more risk sharing. Upon financial integration, capital flows from Foreign (high-margin country) to Home, leading to lower interest rates and a larger global supply of safe assets. Unlike in standard models with partial equity issuance, in our model, Home can lose from financial integration due to the endogenous reduction in risk sharing and aggregate shocks can generate large gross capital flows.     

异质性劳动力供给、工资粘性与中国经济周期

通过同时引入异质性劳动力供给和工资粘性拓展了包含五类外生冲击的新凯恩斯DSGE模型,在此框架下考察异质性劳动力供给和工资粘性对经济周期的作用及传导机制,并分析两者传播和放大外生冲击作用的异同,研究发现：同时包含异质性劳动力供给和工资粘性的一般均衡模型要明显优于非异质性劳动力供给和无工资粘性模型;异质性劳动力供给和工资粘性均在一定程度上放大了外生冲击对经济波动的影响,在不包含两者的情形下,投资冲击的贡献度变小,技术冲击和政府支出冲击的贡献度变大。     

Non-stationary Hours in a DSGE Model

The time series fit of dynamic stochastic general equilibrium (DSGE) models often suffers from restrictions on the long-run dynamics that are at odds with the data. Using Bayesian methods we estimate a stochastic growth model in which hours worked are stationary and a modified version with permanent labor supply shocks. If firms can freely adjust labor inputs, the data support the latter specification. Once we introduce frictions in terms of labor adjustment costs, the overall time series fit improves and the model specification in which labor supply shocks and hours worked are stationary is preferred.     

Financial Intermediaries, Markets, and Growth

We build a model in which financial intermediaries provide insurance to households against idiosyncratic liquidity shocks. Households can invest in financial markets directly if they pay a cost. In equilibrium, the ability of intermediaries to share risk is constrained by the market. From a growth perspective, this can be beneficial because intermediaries invest less in the productive technology when they provide more risk-sharing. Our model predicts that bank-oriented economies can grow more slowly than more market-oriented economies, which is consistent with some recent empirical evidence.     

Optimal consumption and asset allocation with unknown income growth

Recent empirical evidence supports the view that the income process has an individual-specific growth rate component [Baker, M., 1997. Growth-rate heterogeneity and the covariance structure of life-cycle earnings. Journal of Labor Economics 15, 338-375; Guvenen, F., 2007b. Learning your earning: Are labor income shocks really very persistent? American Economic Review 97, 687-712; Huggett, M., Ventura, G., Yaron, A., 2007. Sources of life-cycle inequality. Working paper, University of Pennsylvania]. Moreover, the individual-specific growth component may be stochastic. Motivated by these empirical observations, I study an individual's optimal consumption-saving and portfolio choice problem when he does not observe his income growth. As in standard income fluctuation problems, the individual cannot fully insure himself against income shocks. In addition to the standard income-risk-induced precautionary saving demand, the individual also has learning-induced precautionary saving demand, which is greater when belief is more uncertain. With constant unobserved income growth, changes in belief are not predictable. However, with stationary stochastic income growth, belief is no longer a martingale. Mean reversion of belief reduces hedging demand on average and in turn mitigates the impact of estimation risk on consumption-saving and portfolio decisions.     

Taxes, transfers and employment in an incomplete markets model

The consequences of increases in the scale of tax and transfer programs are assessed in the context of a model with idiosyncratic productivity shocks and incomplete markets. The effects are contrasted with those obtained in a stand-in household model featuring no idiosyncratic shocks and complete markets. The main finding is that the impact on hours remains very large, but the welfare consequences are very different. The analysis also suggests that tax and transfer policies have large effects on average labor productivity via selection effects on employment.     

Disentangling the Short and Long-Run Effects of Occupied Stock in the Rental Adjustment Process

In the current stand of literature on the rental adjustment process starting with Hendershott et al. (Real Estate Economics, 30, 165-183, 2002a, Journal of Real Estate Finance and Economics, 24, 59-87, 2002b) it has become practice to treat the compound variable “occupied stock” as a supply variable. In this study we show that this variable deserves a more critical investigation and that the general view of a supply variable may be misleading. Using panel data covering 30 urban areas for 17 years, we investigate the rental adjustment process in the German office market. The application of recently developed cointegration techniques for non-stationary panel data in conjunction with the corresponding error correction model (ECM) enables us to overcome the data limitations, particularly existent for most European real estate markets. Hence, our primary motivation is (a) to demonstrate how “occupied stock” should be interpreted correctly and (b) to provide useful insights into the long-term relationships and short-run dynamics of real office prime rents. The empirical evidence suggests that a one percent rise in office employment increases real rents on average by 1.64% through higher demand for office space. On the other hand, a one percent increase in the supply of office space decreases real rents in the long run by 2.25%. The results from the error correction model show that deviations from the long-run equilibrium lead to an adjustment process which restores equilibrium within approximately 3 years.     

Idiosyncratic risk and the cross-section of stock returns: Merton (1987) meets Miller (1977)

Merton [1987. A simple model of capital market equilibrium with incomplete information. Journal of Finance 42, 483–510] predicts that idiosyncratic risk should be priced when investors hold sub-optimally diversified portfolios, and cross-sectional stock returns should be positively related to their idiosyncratic risk. However, the literature generally finds a negative relationship between returns and idiosyncratic risk, which is more consistent with Miller's [1977. Risk, uncertainty, and divergence of opinion. Journal of Finance 32, 1151–1168] analysis of asset pricing under short-sale constraints. We examine the cross-sectional effects of idiosyncratic risk while explicitly recognizing the confounding effects that dispersion of beliefs and short-sale constraints produce in the Merton framework. We find strong support for Merton's [1987. A simple model of capital market equilibrium with incomplete information. Journal of Finance 42, 483–510] model among stocks that have low levels of investor recognition and for which short selling is limited. For these stocks, the relation between idiosyncratic risk and expected returns is positive, as predicted by Merton [1987. A simple model of capital market equilibrium with incomplete information. Journal of Finance 42, 483–510].     

Asset pricing with unforeseen contingencies

We investigate an economy of heterogeneous agents that cannot specify all exogenous welfare-relevant events and consequently view the impact of unforeseen contingencies as utility shocks. In this setting we characterize an appropriate market equilibrium concept when securities can trade only on demand- and price-contingent events. We establish the existence of an equilibrium for a class of parametric models in which aggregating taste shocks across agents can lead to nonconsumption pricing factors. To fit the stylized facts, (i) non consumption factors must dominate the pricing kernel and contribute to the variation of the wealth-consumption ratio, (ii) markets must be incomplete and the set of claims that are traded endogenously determined, (iii) agents’ preferences with respect to unforeseen contingencies must be non-expected utility, and, (iv) although non-consumption pricing factors can be conditionally uncorrelated with aggregate consumption shocks, they must be correlated with shocks to expected consumption growth.     

Aggregate Implications of Heterogeneous Households in a Sticky‐Price Model

This paper analyzes the role of heterogeneous households in propagating shocks over the business cycle by generalizing a basic sticky‐price model to allow for imperfect risk sharing between households that differ in labor incomes. I show that imperfectly insured household consumption distorts household incentive to supply labor hours through an idiosyncratic income effect, which in turn generates strategic complementarities in price setting and thus amplifies business cycle fluctuations. This mechanism diminishes the role of nominal rigidities and makes sticky‐price models more consistent with microeconomic evidence on the frequency of price changes.     

Multifrequency news and stock returns

Equity prices are driven by shocks with persistence levels ranging from intraday horizons to several decades. To accommodate this diversity, we introduce a parsimonious equilibrium model with regime shifts of heterogeneous durations in fundamentals, and estimate specifications with up to 256 states on daily aggregate returns. The multifrequency equilibrium has higher likelihood than the Campbell and Hentschel [1992. No news is good news: an asymmetric model of changing volatility in stock returns. Journal of Financial Economics 31, 281–318] specification, while producing volatility feedback 10 to 40 times larger. Furthermore, Bayesian learning about volatility generates a novel trade-off between skewness and kurtosis as information quality varies, complementing the uncertainty channel [e.g., Veronesi, 1999. Stock market overreaction to bad news in good times: a rational expectations equilibrium model. Review of Financial Studies 12, 975–1007]. Economies with intermediate information best match daily returns.