Time-varying idiosyncratic risk and aggregate consumption dynamics

Long-term earnings losses for displaced workers are large and counter-cyclical. Similarly, the skewness of earnings growth rates is strongly pro-cyclical. This paper presents an incomplete markets business cycle model in which idiosyncratic risk varies over time in accordance with these empirical findings. These dynamics of idiosyncratic risk give rise to a cyclical precautionary savings motive that substantially raises the volatility of aggregate consumption growth. According to the model, idiosyncratic risk spiked during the Great Recession, leading to a substantial decline in aggregate consumption.     

Trend in aggregate idiosyncratic volatility

We suggest that price interaction among stocks is an important determinant of idiosyncratic volatility. We demonstrate that as more (less) stocks are listed in the markets, price interaction among stocks increases (decreases), and hence stocks, on average, become more (less) volatile. Our results show that price interaction has a significant positive effect of idiosyncratic volatility. The results of various robustness checks indicate that the effect of price interaction is still significant to the presence of liquidity, newly listed firms, cash flow variables, business cycle variables, and market volatility. Once the price interaction effect is taken into account, no trend remains in idiosyncratic volatility. We conclude that there is no trend, but a reflection of the positive effect of price interaction on idiosyncratic volatility.     

The cross-section of dynamics in idiosyncratic risk

This paper investigates change in idiosyncratic volatility estimated by individual security. We find that a significant portion of securities contains long periods of increasing or decreasing idiosyncratic risk. The series of idiosyncratic risk though are unlikely to have a life-long deterministic trend, and can be often characterized by a long memory process. Our evidence suggests that the proportions of securities with rising and declining risk continuously change, which in turn affects fluctuations of the market average. This evidence implies that an average idiosyncratic risk may not be a good representative of the dynamics in risk of a given security. We demonstrate that the companies with an increasing idiosyncratic risk tend to have deteriorating performance, and investigate factors behind these empirical observations.     

Investment,idiosyncratic risk,and growth options

We provide evidence that growth options play an important role in determining the negative relation between corporate investment and idiosyncratic risk in the absence of agency problem. A simple real options model predicts that the negative relation between corporate investment and idiosyncratic risk is a U-shaped function of the level of idiosyncratic risk: investment responds the most when idiosyncratic risk is at the intermediate level. And the negative relation is stronger when firms possess more growth options. Our results are robust when we control for the effect of managerial risk aversion, supporting the view that firms’ optimal response to uncertainty is an important driving force behind the negative investment–idiosyncratic risk relation.     

Transparency,idiosyncratic risk,and convertible bonds

We first investigate the relationship among a company's information transparency, idiosyncratic risk, and return of its convertible bonds. The effects of a company's idiosyncratic risk on its equity's value volatility and its credit risk are also examined. The findings indicate that when a company discloses a significant amount of information, it is likely to have a higher idiosyncratic risk and a lower credit risk, with no impact on returns on convertible bonds. The volatility of stock returns is positively related to returns on convertible bonds, and it is found that diversified strategies and returns on a company's equity help to improve its credit rating and that a better credit rating triggers an increase in returns on convertible bonds and idiosyncratic risk, indicating that evaluations of the value of convertible bonds must take pure bonds and equity (option) values into account. After excluding conversion values and estimating the idiosyncratic risk on daily, weekly, and monthly bases, this study suggests that there is a positive relation between returns on convertible bonds and information transparency when estimating idiosyncratic risk on a monthly basis and that a positive association also exists between credit rating, idiosyncratic risk, and returns on bonds.     

A framework to measure integrated risk

A framework underlying various models that measure the credit risk of a portfolio is extended in this paper to allow the integration of credit risk with a range of market risks using Monte Carlo simulation. A structural model is proposed that allows interest rates to be stochastic and provides closed-form expressions for the market value of a firm's equity and its probability of default. This model is embedded within the integrated framework and the general approach illustrated by measuring the risk of a foreign exchange forward when there is a significant probability of default by the counterparty. For this example moving from a market risk calculation to an integrated risk calculation reduces the expected future value of the instrument by an amount that could not be calculated using the common pre-settlement exposure technique for estimating the credit risk of a derivative.     

A simple continuous measure of credit risk

This paper introduces a simple parameterization for the risk-neutral default probability distributions for risky firms that are easily computed from quoted bond prices. The corresponding expected times to default have a particularly simple form and are proposed as a measure for credit risk. Being continuous in nature, times to default provide a much finer measure of risk than those provided by ratings agencies. Comparison with the ratings provided by Moody's and the distance to default measures calculated using the Merton [Merton, R. (1974). On the pricing of corporate debt: the risk structure of interest rates. Journal of Finance, 2(2), 449-470] model shows that the highest rank correlation is found between the proposed time to default measure and Moody's ratings.     

Does idiosyncratic risk matter in IPO long-run performance?

Review of Quantitative Finance and Accounting - This paper studies how firm-level idiosyncratic risk varies over time and affects both initial public offering (IPO) and matched non-IPO firms’...     

Do institutional ownership and innovation influence idiosyncratic risk?

Business decisions influence the level of idiosyncratic risk. Several factors that contribute to idiosyncratic risk must be explored. Therefore, we examine the impact of innovation and institutional ownership on idiosyncratic risk for NYSE- and NASDAQ-listed firms. The sample contains 30,888 firm-year observations based on annual data from 2003 to 2016. We use a dynamic panel approach to address potential endogeneity difficulties when analyzing the results. Large-scale innovation activity, institutional investors, and innovation reduce idiosyncratic risk. Furthermore, the interactions between institutional investors and high-level ownership stakeholders considerably minimize idiosyncratic risk. Our study demonstrates that the degree to which firms adopt innovation and institutional ownership may affect firm-specific hazards.     

Estimating the expected marginal rate of substitution: A systematic exploitation of idiosyncratic risk

We develop a methodology to estimate the shadow risk free rate or expected intertemporal marginal rate of substitution, “EMRS”. Our technique relies upon exploiting idiosyncratic risk, since theory dictates that idiosyncratic shocks earn the EMRS. We apply our methodology to recent monthly and daily data sets for the New York and Toronto Stock Exchanges. We estimate EMRS with precision and considerable time-series volatility, subject to an identification assumption. Both markets seem to be internally integrated; different assets traded on a given market share the same EMRS. We reject integration between the stock markets, and between stock and money markets.     

The LIX: A model-independent liquidity index

This paper provides a new model-free indicator of liquidity, the so-called LIX index. The computation of the LIX index combines the conic finance theory, which recognizes the two-price economy and is built upon the concept of indices of acceptability of Cherny and Madan (2010), with the option payoff spanning formula of Breeden and Litzenberger (1978). Matching the conic finance bid and ask prices of the stock with those observed in the market allows us to derive a model-free and unit-less indicator of spot liquidity. Just as the VIX and the SKEW index quantify the volatility and the tail risk perceived by today’s investors, the resulting LIX index measures, in a similar market-implied fashion, the liquidity risk. The maximum likelihood estimation of popular mean-reverting processes applied to model-free liquidity time series indicates that spot liquidity tends to dry up during distress periods whereas a global drying-up of liquidity could not be detected during turmoil periods in the option market.     

Annuitization and aggregate mortality risk

It is well established that annuities can fully diversify idiosyncratic mortality risks. However, survival rates at the cohort level are changing, raising the question what is the scope of annuities in the presence of aggregate mortality risk? In an overlapping generations setting, we show that risk free annuities exist, but offer a return below the (fair) certainty equivalent return, and agents do not fully annuitize their savings. Higher aggregate mortality risk increases savings and thus the mean level of the capital stock. This lowers the mean rate of return on capital, the survival premium on annuities and the share of individual savings in annuities.     

Is information risk priced? Evidence from abnormal idiosyncratic volatility

We propose a new, price-based measure of information risk called abnormal idiosyncratic volatility (AIV) that captures information asymmetry faced by uninformed investors. AIV is the idiosyncratic volatility prior to information events in excess of normal levels. Using earnings announcements as information events, we show that AIV is positively associated with informed return run-ups, abnormal insider trading, short selling, and institutional trading during pre-earnings-announcement periods. We find that stocks with high AIV earn economically and statistically larger future returns than stocks with low AIV. Taken together, our findings support the notion that information risk is priced.     

Costly arbitrage and idiosyncratic risk: Evidence from short sellers

Previous studies have shown that high short interest stocks have low subsequent returns. We test whether the persistence of this effect is due to costs limiting arbitrage. The arbitrage cost that we focus on is idiosyncratic risk which, regardless of the arbitrageur’s level of diversification, deters arbitrage activity. Consistent with costly arbitrage, we find that among high short interest stocks a one standard deviation increase in idiosyncratic risk predicts a more than 1% decline in monthly returns. Moreover, idiosyncratic risk does not predict returns across low short interest stocks, and short interest does not predict low returns across low idiosyncratic risk stocks. Our results are robust to commonly used proxies for both transaction costs and short sale constraints.     

Daily short interest,idiosyncratic risk,and stock returns

This paper examines the relation between short selling and returns and the impact of arbitrage costs on short sellers’ behavior. Using daily UK short selling data, we find that stocks with low short interest levels experience significant positive returns on both an equal- and value-weighted basis. Economic theory predicts that short sellers avoid establishing positions in stocks with high idiosyncratic risk. Our results indicate a negative relation between short interest and returns among high idiosyncratic risk stocks and that short selling activity is mostly concentrated in low idiosyncratic risk stocks where it is less costly to arbitrage fundamental risk.     

Retail investor attention and firms' idiosyncratic risk: Evidence from China

This paper investigates retail investor attention to firms' idiosyncratic risk in China. We use the Baidu search index as a proxy for attention and test its effect on Chinese firms' idiosyncratic risk from 2011 to 2017. Our empirical results suggest investor attention has a positive impact on firms' idiosyncratic risk. This effect is robust to possible endogeneity issues and alternative channels of effects and is stronger for small firms. Additional analysis finds that the effect of our proxy for attention on firms' idiosyncratic risk is stronger than investor sentiment and traditional attention proxies, including announcements, media news, analyst ratings, and brokerage reports. These findings provide evidence of retail investor attention could increase firms' contemporaneous idiosyncratic risk, and decrease firms' subsequent period risk.     

Technological innovations and aggregate risk premiums

In this paper, I propose that technological innovations increase expected stock returns and premiums at the aggregate level. I use aggregate patent data and research and development (R&D) data to measure technological innovations in the U.S., and find that patent shocks and R&D shocks have positive and distinct predictive power for U.S. market returns and premiums. Similar patterns are also found in international data including other G7 countries, China, and India. These findings are consistent with previous empirical studies based on firm-level data, and call for further theoretical explanations.     

Counterparty risk,central counterparty clearing and aggregate risk

I construct a model of bilateral trading of over-the-counter (OTC) derivatives to study the performance of central counterparty (CCP) clearing. I first show how buyers are exposed to counterparty risk under bilateral clearing. I then show how a CCP can fully insure against counterparty risk through risk-mutualization and achieve full idiosyncratic risk-sharing among market participants. I further demonstrate the impact of aggregate risk on CCP clearing and illustrate a scenario in which the CCP fails to provide full insurance against counterparty risk and full idiosyncratic risk-sharing collapses under severe aggregate risk. To insure against aggregate risk and retain full idiosyncratic risk-sharing, sellers’ capital resource is important on top of CCP mutualization. Finally, I allow buyers to costly search for sellers and study the implications of optimal search effort. I show how a moral hazard problem can arise if effort is unobservable, in which case full CCP insurance against counterparty risk is no longer optimal.