Working Papers
How does Insurance Competition Affect Medical Consumption?, January 2023
Competition in insurance markets affects not only the premium but also the cost-sharing terms---e.g. copays and coinsurance rates--- which may affect a patient's medical decisions and health outcomes. Using medical claims data linked to insurance product choices, I estimate a model in which consumers select an insurance plan and make medical consumption decisions given the cost-sharing terms of their insurance. Firms compete on both the premium and the copay for primary care. A $10 increase in the copay leads to an 8% decrease in medical consumption and a 0.3 percentage point increase in inpatient mortality. Mergers have heterogeneous effects on the primary care copay, leading to between a $6 reduction and $24 increase in mean annual medical consumption. At typical estimates of the value of a statistical life, mergers that increase medical consumption improve welfare as the additional resource use is outweighed by a reduction in mortality risk.
Mergers in the Presence of Adverse Selection, April 2023
In the presence of adverse selection, a merger can potentially lead to greater social welfare. To see this, consider that a firm has an incentive to offer a product that appeals to low-risk consumers and encourages high-risk consumers to purchase from a competitor. This distortion declines with fewer competitors and is absent in a monopoly. Whether or not this welfare benefit is sufficient to offset the welfare cost of greater markups is an empirical question that depends on the merger. In this paper, I show how this trade-off can be captured in an empirically tractable discrete choice model and apply the model to a proposed merger in the non-group insurance market regulated by the ACA. Even in the presence of transfers to address adverse selection, 13% of mergers lead to greater consumer surplus. In markets where the sorting distortion is greater than $7.5 per person, more than 1 out of 3 mergers improve consumer surplus. This highlights that antitrust enforcement and other policies that encourage competition are complements to regulations targeting adverse selection.
A Tractable Income Process for Business Cycle Analysis (with Fatih Guvenen and Alisdair McKay), February 2022
We estimate a parsimonious income process that is consistent with several key features of how income risk varies over the business cycle. In particular, the estimated process generates year-to-year income changes that (i) have flat and acyclical variance, (ii) have volatile and procyclical skewness, (iii) have very high kurtosis, and (iv) imply a moderate rise in cross-sectional inequality over the life cycle consistent with the US data. Furthermore, the process also captures the predictable nature of business cycle income risk: income changes during a business cycle episode are partly predicted by income levels before that episode. The estimated process features a time-varying distribution of innovations as well as a factor structure for business cycle exposure.
Competition in insurance markets affects not only the premium but also the cost-sharing terms---e.g. copays and coinsurance rates--- which may affect a patient's medical decisions and health outcomes. Using medical claims data linked to insurance product choices, I estimate a model in which consumers select an insurance plan and make medical consumption decisions given the cost-sharing terms of their insurance. Firms compete on both the premium and the copay for primary care. A $10 increase in the copay leads to an 8% decrease in medical consumption and a 0.3 percentage point increase in inpatient mortality. Mergers have heterogeneous effects on the primary care copay, leading to between a $6 reduction and $24 increase in mean annual medical consumption. At typical estimates of the value of a statistical life, mergers that increase medical consumption improve welfare as the additional resource use is outweighed by a reduction in mortality risk.
Mergers in the Presence of Adverse Selection, April 2023
In the presence of adverse selection, a merger can potentially lead to greater social welfare. To see this, consider that a firm has an incentive to offer a product that appeals to low-risk consumers and encourages high-risk consumers to purchase from a competitor. This distortion declines with fewer competitors and is absent in a monopoly. Whether or not this welfare benefit is sufficient to offset the welfare cost of greater markups is an empirical question that depends on the merger. In this paper, I show how this trade-off can be captured in an empirically tractable discrete choice model and apply the model to a proposed merger in the non-group insurance market regulated by the ACA. Even in the presence of transfers to address adverse selection, 13% of mergers lead to greater consumer surplus. In markets where the sorting distortion is greater than $7.5 per person, more than 1 out of 3 mergers improve consumer surplus. This highlights that antitrust enforcement and other policies that encourage competition are complements to regulations targeting adverse selection.
A Tractable Income Process for Business Cycle Analysis (with Fatih Guvenen and Alisdair McKay), February 2022
We estimate a parsimonious income process that is consistent with several key features of how income risk varies over the business cycle. In particular, the estimated process generates year-to-year income changes that (i) have flat and acyclical variance, (ii) have volatile and procyclical skewness, (iii) have very high kurtosis, and (iv) imply a moderate rise in cross-sectional inequality over the life cycle consistent with the US data. Furthermore, the process also captures the predictable nature of business cycle income risk: income changes during a business cycle episode are partly predicted by income levels before that episode. The estimated process features a time-varying distribution of innovations as well as a factor structure for business cycle exposure.
Publications
Sources of Inertia in Health Plan Choice in the Individual Health Insurance Market (with Coleman Drake and Bryan Dowd),
November 2021 (forthcoming, Journal of Public Economics)
The Demand for Individual Insurance: Evidence from a Private Online Marketplace (with Roger Feldman and Stephen Parente),
August 2021 (forthcoming, American Journal of Health Economics)
Upward Pricing Pressure as a Predictor of Merger Price Effects (with Nathan Miller, Marc Remer, and Gloria Sheu), International Journal of Industrial Organization, 52, 2017: 216-247
Pass-Through and the Prediction of Merger Price Effects (with Nathan Miller, Marc Remer, and Gloria Sheu), Journal of Industrial Economics, 64(4) 201, 2016: 683-709.
November 2021 (forthcoming, Journal of Public Economics)
The Demand for Individual Insurance: Evidence from a Private Online Marketplace (with Roger Feldman and Stephen Parente),
August 2021 (forthcoming, American Journal of Health Economics)
Upward Pricing Pressure as a Predictor of Merger Price Effects (with Nathan Miller, Marc Remer, and Gloria Sheu), International Journal of Industrial Organization, 52, 2017: 216-247
Pass-Through and the Prediction of Merger Price Effects (with Nathan Miller, Marc Remer, and Gloria Sheu), Journal of Industrial Economics, 64(4) 201, 2016: 683-709.
