Regional variations in medical spending and utilization: a longitudinal analysis of US Medicare population
利用1974-2003年Medicare受益人5%样本的纵向数据，发现各州医疗支出与利用差异显著，但随时间推移有所缩小，尤其在改革后，控制人口、供需因素后差异仍存。
One of the perceived symptoms of US Medicare inefficiency is the existence of the dramatic variation in spending and utilization in different areas of the country. This study uses the Continuous Medicare History Sample, a large longitudinal 5% sample of all Medicare beneficiaries from 1974 to 2003, to study the issue. We show that the spending and utilization disparities are significant at the aggregate state level. More importantly, the variation shows signs of narrowing over time, particularly in the earlier years of the sample period and in some cases following major reforms. However, it remains significant even after an array of demographic, demand and supply side factors are controlled for.