THE PRICE SENSITIVITY OF MEDICARE BENEFICIARIES: A REGRESSION DISCONTINUITY APPROACH
利用密歇根大学退休人员健康福利计划4年数据，通过断点回归分析发现，月保费每增加10美元，健康计划市场份额下降2-3个百分点，对研究医保定价和消费者行为有参考价值。
We use 4 years of data from the retiree health benefits program of the University of Michigan to estimate the effect of price on the health plan choices of Medicare beneficiaries. During the period of our analysis, changes in the University's premium contribution rules led to substantial price changes. A key feature of this 'natural experiment' is that individuals who had retired before a certain date were exempted from having to pay any premium contributions. This 'grandfathering' creates quasi-experimental variation that is ideal for estimating the effect of price. Using regression discontinuity methods, we compare the plan choices of individuals who retired just after the grandfathering cutoff date and were therefore exposed to significant price changes to the choices of a 'control group' of individuals who retired just before that date and therefore did not experience the price changes. The results indicate a statistically significant effect of price, with a $10 increase in monthly premium contributions leading to a 2 to 3 percentage point decrease in a plan's market share.