title: Less, not more, HMO competition leads to better plan performance.
mesh_terms: D019985:Benchmarking; D004465:Economic Competition / Q000706:statistics & numerical data; D006279:Health Maintenance Organizations / Q000592:standards* / Q000706:statistics & numerical data*; D006801:Humans; D018803:Models, Economic; D019984:Quality Indicators, Health Care / Q000191:economics*; D014481:United States