Definition
Moral hazard in insurance is the tendency of insured parties to alter their behavior in ways that increase the probability or magnitude of an insured loss, or the generosity of a claim, because the insurance shifts the cost of adverse outcomes from the individual to the insurer. The concept originates in contract theory (Arrow 1963; Pauly 1968): insurance that is actuarially fair for a given risk level changes the effective price of the insured risk, inducing behavioral responses that raise expected losses and therefore the actuarially fair premium — a welfare-reducing equilibrium unless partially offset by the insurance value of consumption smoothing. In disability insurance (DI), the principal moral hazard channel is the accession margin: more generous replacement rates or easier eligibility induce additional claims from workers who are on the margin between filing and continuing to work.
Key Ideas
- Ex ante vs. ex post moral hazard: Ex ante moral hazard is reduced precaution before a loss (e.g., workers in generous DI systems take more occupational risks). Ex post moral hazard inflates claims after the triggering event (malingering, delayed recovery, strategic non-return to work). In private long-term disability (LTD), both operate but the accession-margin response (filing decision) is the empirically dominant channel.
- Replacement rate (RR) elasticity: Autor, Duggan, and Gruber (2014) estimate the elasticity of LTD accessions with respect to the replacement rate at ≈4.0 for raw accessions; cap-adjusted (removing the mechanical effect of the benefit cap on effective RR variation), the elasticity is ≈1.4. Both far exceed Social Security Disability Insurance (SSDI) accession elasticity estimates, reflecting LTD's shorter benefit periods and higher exit rates.
- Elimination period (EP) as deterrence device: A longer waiting period before benefit payments raises the effective cost of filing, deterring marginal claimants. The behavioral component of EP deterrence (≈40% of the total EP accession effect) represents a form of moral hazard management by plan design. See Elimination Period and Forward-Looking Moral Hazard.
- Selection on severity: Moral hazard responses are concentrated among workers with less severe impairments (those for whom the decision to file is genuinely marginal). Workers with severe permanent disabilities are not deterred by plan parameters — they file regardless. This selection means that policies reducing moral hazard (longer EP, lower RR) improve the average severity of the claimant pool.
- Heterogeneous moral hazard and selection on it (Einav et al. 2013): Moral hazard is not uniform across individuals — in health insurance (Alcoa Inc. employees), the standard deviation of individual moral hazard responses ($3,200) exceeds twice the mean ($1,330), with coefficient of variation (CV) > 2. More importantly, individuals select insurance coverage based on their anticipated moral hazard response: higher-moral-hazard types prefer more comprehensive plans. This "selection on moral hazard" is roughly as quantitatively important as traditional selection on health risk: moving from 10th to 90th percentile of the moral hazard distribution reduces demand for the high-deductible plan by 23 pp; the comparable health risk effect is 24 pp. Policy implication: when only a minority voluntarily adopt high-deductible plans, the average spending reduction is far below the population average because low-moral-hazard types self-select in first. Standard randomized estimates overstate the savings from voluntary high-deductible plan adoption. See Liran Einav and Amy Finkelstein.
- Optimal insurance tradeoff: The welfare cost of moral hazard must be weighed against the insurance value of disability benefits for workers who cannot smooth consumption otherwise. The Baily-Chetty sufficient statistics framework captures this tradeoff formally: optimal benefit generosity equates the marginal insurance value to the marginal deadweight loss from behavioral distortion. See Optimal Social Insurance.
Why It Matters
- Plan design: Replacement rate, elimination period, and benefit caps are the three levers through which employers and insurers manage moral hazard in LTD. The empirical elasticity estimates quantify how sensitive accessions are to each parameter.
- SSDI policy: The DI replacement rate mechanically rose in the 1980s–2000s as low-skill wages fell while the Social Security Administration (SSA) wage index continued rising, increasing the moral hazard margin for low-wage workers. See DI Replacement Rate.
- Fundamental tension: A well-targeted disability insurance system should deter low-severity claimants (moral hazard management) without deterring high-severity claimants (accurate coverage). EP and the sequential determination process are partial solutions; neither fully resolves the asymmetric-information problem.
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