Consumers Buy Lower-Cost Plans On Covered California, Suggesting Exposure To Premium Increases Is Less Than Commonly Reported.

With the notable exception of California, states have not made enrollment data for their Affordable Care Act (ACA) Marketplace plans publicly available. Researchers thus have tracked premium trends by calculating changes in the average price for plans offered (a straight average across plans) rather than for plans purchased (a weighted average). Using publicly available enrollment data for Covered California, we found that the average purchased price for all plans was 11.6 percent less than the average offered price in 2014, 13.2 percent less in 2015, and 15.2 percent less in 2016. Premium growth measured by plans purchased was roughly 2 percentage points less than when measured by plans offered in 2014-15 and 2015-16. We observed shifts in consumer choices toward less costly plans, both between and within tiers, and we estimate that a $100 increase in a plan's net annual premium reduces its probability of selection. These findings suggest that the Marketplaces are helping consumers moderate premium cost growth.

除加利福尼亚州这一显著例外，其他各州并未公开其《平价医疗法案》（ACA）市场计划的参保数据。因此，研究人员通过计算所提供计划（各计划的简单平均）而非所购买计划（加权平均）的平均价格变化来追踪保费趋势。利用加州医保（Covered California）公开的参保数据，我们发现，2014年所有计划的平均购买价格比平均提供价格低11.6%，2015年低13.2%，2016年低15.2%。2014 - 2015年以及2015 - 2016年，按所购买计划衡量的保费增长幅度比按所提供计划衡量的大约低2个百分点。我们观察到，消费者的选择在不同层级之间以及同一层级内部都朝着成本更低的计划转移，而且我们估计，一项计划的年度净保费每增加100美元，其被选中的概率就会降低。这些研究结果表明，医保市场正在帮助消费者缓解保费成本的增长。