Consumer choice policies may improve the matching of consumers and providers, and may spur competition over quality dimensions relevant to consumers. However, the gains from choice may fail to materialise in markets characterised by information frictions and switching costs. We use two large-scale randomised field experiments in primary health care to examine if individuals reconsider their provider choice when receiving leaflets with comparative information and pre-paid choice forms by postal mail. The first experiment targeted a representative subset of the 1.3 million residents in a Swedish region. The second targeted new residents in the same region, a group expected to have less prior information and lower switching costs than the general population. The propensity to switch providers increased after the interventions in both the population-representative sample (by 0.6–0.8 percentage points, 10–14%) and among new residents (2.3 percentage points, 26%). The results demonstrate that there are demand side frictions in the primary care market. Exploratory analyses indicate that the effects on switching were larger in urban markets and that the interventions had heterogeneous effects on the type of providers chosen, and on health care and drug consumption.

消费者选择政策可以改善消费者和提供者的匹配度，并可以刺激与消费者相关的质量维度上的竞争。但是，选择的收益可能无法在以信息摩擦和转换成本为特征的市场中实现。我们在初级卫生保健中使用了两个大规模的随机领域实验，以检查个人在收到带有比较信息和通过邮寄方式预付的选择表格的传单时，是否重新考虑其提供者的选择。第一个实验针对的是瑞典地区130万居民的代表性子集。第二个目标是同一地区的新居民，该群体预计比一般人口拥有更少的先验信息和较低的转换成本。在人口代表性样本（增加0.6-0.8个百分点，10-14％）和新居民（增加2.3个百分点，26％）之后，更换提供者的意愿有所增加。结果表明，初级保健市场存在需求方面的摩擦。探索性分析表明，在城市市场中，对转换的影响更大，并且干预措施对所选择的提供者的类型，医疗保健和药物消费产生不同的影响。