Pre-analysis plan: The Causal Effects of the Finnish Guarantee Pension on Health

This pre-analysis plan outlines the research design for estimating the causal effects of the Finnish guarantee pension—a minimum income floor for pension recipients—on mortality, morbidity, and prescription drug use. The 2011 reform generated a discrete change in the slope of the benefit schedule for low-income pensioners, creating a plausibly exogenous source of variation. We exploit this reform using a Difference-in-Kinks (DiK) estimator that compares changes in outcome gradients around the policy kink before and after the reform. The analysis is conducted using comprehensive Finnish administrative data from population registers, hospital records, prescription drug reimbursement databases, and pension and tax registers. Primary outcomes include all-cause mortality, inpatient hospital days, and annual prescription drug co-payments. Secondary analyses focus on alcohol-related mortality and mental-health-related medication use. We further examine the potential heterogeneity of the effects by gender. The PAP pre-specifies the hypotheses, outcome definitions, sample restrictions, identification assumptions, and estimation equations. All analyses will be implemented without additional controls, and all deviations from the pre-analysis plan will be transparently documented in the final study.