数学中国w, madio,net The Mas! Expensive is Not the Best 155 The Most Expensive is Not the best Hongxing Hao Xiangrong Zer Boliang Sun National University of Defense Technology Changsha, Chin Advisor: Ziyang mao Abstract Motivated to evaluate healthcare systems more accurately, we analyze existing evaluation methods. Most methods mainly focus on outcomes and their metrics often ignore intemal characteristics of the healthcare systems. We devise two methods: animproved World Health Organization(WHO) method and a comprehensive evaluation method Theimproved WHO method uses the same metrics as the WHOmethod which are determined by the outcomes of the healthcare system. Our im- provement is to use a grey comprehensive evaluation and the principle of minimum loss of information to combine the metrics, rather than simply combining them linearly. In our comprehensive evaluation method, we define five new metrics that concern both outcomes and characteristics of the healthcare system itself, including the effect of the government and the basic situation of a country. Then we use the equal-interval method to get a final score. Compared with other methods, this one does a better job in distinguishing countries and in sensitivit After comparing with other four countries that represent the four main modes of healthcare systems, we conclude that the most important reason why the highest cost can't make the U.S. the best is unfairness. Afterward, we use a neural network algorithm to predict what will happen to the us. if some values of the metrics change. We conclude that the U.S. can get the greatest benefit by improving fairness We finally consider a policy change, a"medical insurance voucher"as a method to increase insurance coverage and reduce unfaimess The UMAP Journnl29(2)(2008)155-168. Copyright2008 by COMAP Inc. All rights reserved. Permission to make digital or hard copies of part or all of this work for personal or dassroom use is granted without tee provided that copies are not made or distributed for profit or commercial dvantage and that copies bear this notice. Abstracting with credit is permitted but copyrights for components of this work owned by others than COMAP must be honored. To copy otherwise, to republish, to post on servers, or to redistribute to lists requires prior permission from COMAP数学中国 www.madio.net