Comparing Price Levels across Countries Using Minimum-Spanning Trees
展示如何通过最小生成树链接双边价格指数来比较多国价格水平，并论证应选择对双边公式最不敏感的树，用Kruskal算法计算，结果与Penn世界表对比。
It is shown how a comparison of price levels across a group of countries can be made by chaining bilateral price indexes across a spanning tree. It is argued that we should use the spanning tree whose resulting multilateral price indexes are least sensitive to the choice of bilateral formula. This minimum-spanning tree can be easily computed using Kruskal's algorithm. Results obtained by chaining Fisher indexes across a minimum-spanning tree are compared with the Penn World Table. © 1999 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology