In the 1990s, Roth applied it to the market for allocating US student doctors to hospitals. He developed a new algorithm that was adopted by the National Resident Matching Program, which helps match resident doctors with the right hospitals.
紧接着地球研究所上一年的榜单，整个全球调查跨越2010到2012。尽管“在过去的五年间，整个世界变得更快乐，更慷慨了一点，” 但在另一些国家，由于经济或政治上的动荡，人民的幸福感却大幅降低。