Knowledge that Transforms

Despite facing significant uncertainty about their lifespans and health care costs, most retirees do not buy annuities or long-term care insurance. In this paper, I find that retirees’ saving and insurance choices are highly inconsistent with standard life-cycle models in which people care only about their own consumption but match well models in which bequests are luxury goods. Bequest motives tend to reduce the value of insurance by reducing the opportunity cost of precautionary saving. The results suggest that bequest motives significantly increase saving and significantly decrease purchases of long-term care insurance and annuities.

We use an event study approach to examine the economic consequences of hospital admissions for adults in two datasets: survey data from the Health and Retirement Study, and hospitalization data linked to credit reports. For non-elderly adults with health insurance, hospital admissions increase out-of-pocket medical spending, unpaid medical bills, and bankruptcy, and reduce earnings, income, access to credit, and consumer borrowing. The earnings decline is substantial compared to the out-of-pocket spending increase, and is minimally insured prior to age-eligibility for Social Security Retirement Income. Relative to the insured non-elderly, the uninsured non-elderly experience much larger increases in unpaid medical bills and bankruptcy rates following a hospital admission. Hospital admissions trigger fewer than 5 percent of all bankruptcies in our sample.

Market economies are intrinsically unstable. The standard search model of equilibrium unemployment, once solved accurately with a globally nonlinear algorithm, gives rise endogenously to rare disasters. Intuitively, in the presence of cumulatively large negative shocks, inertial wages remain relatively high, and reduce profits. The marginal costs of hiring run into downward rigidity, which stems from the trading externality of the matching process, and fail to decline relative to profits. Inertial wages and rigid hiring costs combine to stifle job creation flows, depressing the economy into disasters. The disaster dynamics are robust to extensions to home production, capital accumulation, and recursive utility. (JEL E22, E23, E24, E32, J41, J63, N12)

We consider the classic problem of estimating group treatment effects when individuals sort based on observed and unobserved characteristics. Using a standard choice model, we show that controlling for group averages of observed individual characteristics potentially absorbs all the across-group variation in unobservable individual characteristics. We use this insight to bound the treatment effect variance of school systems and associated neighborhoods for various outcomes. Across multiple datasets, we find that a ninetieth versus tenth percentile school/neighborhood increases the high school graduation probability and college enrollment probability by at least 0.04 and 0.11 and permanent wages by 13.7 percent. (JEL C51, H75, I21, I26, J24, J31, R23)

We study how monetary policy in China influences banks’ shadow banking activities. We develop and estimate the endogenously switching monetary policy rule that is based on institutional facts and at the same time tractable in the spirit of Taylor (1993). This development, along with two newly constructed micro banking datasets, enables us to establish the following empirical evidence. Contractionary monetary policy during 2009–2015 caused shadow banking loans to rise rapidly, offsetting the expected decline of traditional bank loans and hampering the effectiveness of monetary policy on total bank credit. We advance a theoretical explanation of our empirical findings. (JEL E32, E52, G21, O16, O23, P24, P34)

This paper investigates the role of individual firms in international business-cycle comovement using data covering the universe of French firm-level value added and international linkages over the period 1993–2007. At the micro level, trade and multinational linkages with a particular foreign country are associated with a significantly higher correlation between a firm and that foreign country. The impact of direct linkages on comovement at the micro level has significant macro implications. Without those linkages the correlation between France and foreign countries would fall by about 0.098, or one-third of the observed average correlation of 0.291 in our sample of partner countries. (JEL F14, F23, F44, F62, L14)

Investors implement projects based on idiosyncratic signal observations, without knowing how signals and returns are jointly distributed. The following heuristic is studied: investors collect information on previously implemented projects with the same signal realization, and invest if the associated mean return exceeds the cost. The corresponding steady states result in suboptimal investments, due to selection bias and the heterogeneity of signals across investors. When higher signals are associated with higher returns, investors are overoptimistic, resulting in overinvestment. Rational investors increase the overoptimism of sampling investors, thereby illustrating a negative externality imposed by rational investors. (JEL D82, G11, G31, L26, M13)

This paper studies the impact of advertising as a channel for risk selection in Medicare Advantage. We provide evidence that insurer advertising is responsive to the gains from risk selection. Then we develop and estimate an equilibrium model of Medicare Advantage with advertising, allowing rich individual heterogeneity. Our estimates show that advertising is effective in attracting healthy individuals who are newly eligible for Medicare, contributing to advantageous selection into Medicare Advantage. Moreover, risk selection through advertising substantially lowers premiums by improving insurers' risk pools. The distributional implication is that unhealthy consumers may be better off through cross-subsidization from healthy individuals.

We develop an equilibrium model of firm dynamics with random search in the labor market where hiring firms exert recruiting effort by spending resources to fill vacancies faster. Consistent with microevidence, fast-growing firms invest more in recruiting activities and achieve higher job-filling rates. These hiring decisions of firms aggregate into an index of economy-wide recruiting intensity. We study how aggregate shocks transmit to recruiting intensity, and whether this channel can account for the dynamics of aggregate matching efficiency during the Great Recession. Productivity and financial shocks lead to sizable procyclical fluctuations in matching efficiency through recruiting effort. Quantitatively, the main mechanism is that firms attain their employment targets by adjusting their recruiting effort in response to movements in labor market slackness. (JEL D22, E24, E32, J23, J41, J63, M51)

A quantitative model brings together theories linking international trade to quality, technology, and demand for skills. Standard effects of trade on importers and exporters are magnified through domestic input linkages. We estimate the model with data from Colombian manufacturing firms before the 1991 trade liberalization. A counterfactual trade liberalization is broadly consistent with post-liberalization data. It increases skill intensity from 12 to 16 percent, while decreasing sales. Imported inputs, estimated to be of higher quality, and domestic input linkages are quantitatively important. Economies of scale, export expansion, and reallocation of production are small and cannot explain post-liberalization data. (JEL F14, F16, J24, L60, O14, O19, O33)