Motohiro Yogo is a professor of economics at Princeton University. He is also a research associate of the NBER and a co-director of the NBER Insurance Working Group. Prior to joining Princeton in 2015, he held research and teaching positions at the Federal Reserve Bank of Minneapolis and Wharton. He earned a Ph.D. in economics from Harvard in 2004 and an A.B. summa cum laude from Princeton in 2000.
His fields of expertise are financial economics, insurance, and econometrics. His current research is on the impact of institutional investors on asset prices and on the importance of risk and regulation in insurance markets. His research has been supported by grants from the National Science Foundation, the National Institute on Aging, and the Social Security Administration. He has received various awards for his work including the Richard A. Crowell Memorial Prize, the Roger F. Murray Prize, Swiss Finance Institute Outstanding Paper Award, and the Zellner Thesis Award in Business and Economic Statistics.
The magnitude of and heterogeneity in systematic earnings risk has important implications for various theories in macro, labor, and ﬁnancial economics. Using administrative data, we document how the aggregate risk exposure of individual earnings to GDP and stock returns varies across gender, age, the worker’s earnings level, and industry. Aggregate risk exposure is U-shaped with respect to the earnings level. In the middle of the earnings distribution, aggregate risk exposure is higher for males, younger workers, and those in construction and durable manufacturing. At the top of the earnings distribution, aggregate risk exposure is higher for older workers and those in ﬁnance. Workers in larger employers are less exposed to aggregate risk, but they are more exposed to a common factor in employer-level earnings, especially at the top of the earnings distribution. Within an employer, higher-paid workers have higher exposure to employer-level risk than lower-paid workers.
We develop an asset pricing model with rich heterogeneity in asset demand across investors, designed to match institutional holdings. The equilibrium price vector is uniquely determined by market clearing for each asset. We relate our model to traditional frameworks including Euler equations, mean-variance portfolio choice, factor models, and Fama-MacBeth regressions. Because the asset demand system cannot be estimated consistently by least squares in the presence of price impact, we propose two identification strategies, based on a coefficient restriction or instrumental variables. We apply our model to understand the role of institutions in stock market movements, liquidity, volatility, and predictability.
Liabilities ceded by life insurers to shadow reinsurers (i.e., less regulated and unrated off-balance-sheet entities) grew from $11 billion in 2002 to $364 billion in 2012. Life insurers using shadow insurance, which capture half of the market share, ceded 25 cents of every dollar insured to shadow reinsurers in 2012, up from 2 cents in 2002. Our adjustment for shadow insurance reduces risk-based capital by 53 percentage points (or 3 rating notches) and increases default probabilities by a factor of 3.5. We develop a structural model of the life insurance industry and estimate the impact of current policy proposals to limit or eliminate shadow insurance. In the counterfactual without shadow insurance, the average company using shadow insurance would raise prices by 10 to 21 percent, and annual life insurance underwritten would fall by 7 to 16 percent for the industry.
We develop a pair of risk measures, health and mortality delta, for the universe of life and health insurance products. A life-cycle model of insurance choice simplifies to replicating the optimal health and mortality delta through a portfolio of insurance products. We estimate the model to explain the observed variation in health and mortality delta implied by the ownership of life insurance, annuities including private pensions, and long-term care insurance in the Health and Retirement Study. For the median household aged 51 to 57, the lifetime welfare cost of market incompleteness and suboptimal choice is 3.2% of total wealth.
During the financial crisis, life insurers sold long-term policies at deep discounts relative to actuarial value. The average markup was as low as −19 percent for annuities and −57 percent for life insurance. This extraordinary pricing behavior was due to financial and product market frictions, interacting with statutory reserve regulation that allowed life insurers to record far less than a dollar of reserve per dollar of future insurance liability. We identify the shadow cost of capital through exogenous variation in required reserves across different types of policies. The shadow cost was $0.96 per dollar of statutory capital for the average company in November 2008.
The financial crisis of 2008 exposed important vulnerabilities in the banking sector. In its aftermath, considerable academic effort has been devoted to better understanding banking risks, and policymakers around the world are developing new regulations to contain those risks.
Our recent and ongoing work shows that there are also important risks in the insurance sector. Although these risks have been growing rapidly over the past 15 years, they have received relatively little attention from academics and regulators. If unaddressed, these risks could cause severe problems. Insurance is a large share of the financial sector. For example, U.S. life insurance liabilities amounted to $4.1 trillion in 2012, compared to $7 trillion in U.S. savings deposits. Moreover, as the largest institutional investors in the corporate bond market, insurance companies serve an important role in real investment and economic activity.
We begin this note by describing the growing risks and highlight some early symptoms, based on evidence during the financial crisis. We follow with a discussion of possible economic consequences of trouble in the insurance sector. Finally, we highlight points of attention for policymakers and discuss recent developments in global insurance markets.