On the Evolution of the World Income Distribution
研究了1960年至1988年间世界收入分配从正态分布向双峰分布的转变，并预测未来美国将失去人均GDP最高地位，富国增多、穷国减少。
The post-World War I period has seen substantial changes in the world income distribution. As a result, the shape of the distribution has changed from something that looks like a normal distribution in 1960 to a bimodal 'twin peaks' distribution in 1988. Projecting these changes into the future suggests a number of interesting findings. First, it seems likely that the United States will lose its position as the country with the highest level of GDP per worker. Second, the future income distribution will involve far more 'rich' countries and far fewer 'poor' countries than currently observed.