George Kingsley Zipf

George Kingsley Zipf (pronounced [ˈzɪf]), (1902–1950), was an American linguist and philologist who studied statistical occurrences in different languages. Zipf was Chairman of the German Department and University Lecturer (meaning he could teach any subject he chose) at Harvard University. He worked with Chinese languages and demographics, and much of his effort can explain properties of the Internet, distribution of income within nations, and many other collections of data.

Zipf's law
George Kingsley Zipf is the eponym of Zipf's law, which states that while only a few words are used very often, many or most are used rarely,


 * $$P_n \sim 1/n^a$$

where Pn is the frequency of a word ranked nth and the exponent a is almost 1. This means that the second item occurs approximately 1/2 as often as the first, and the third item 1/3 as often as the first, and so on. .

The rank vs. frequency distribution of individual incomes in a unified nation approximates this law. Breaks in this "normal curve of income distribution" portend social pressure for change, even revolution. This is demonstrated in his 1941 book, "National Unity and Disunity" in which the break in the curve of income distribution in 1940 in Indonesia predicts revolution there. Revolution began five years later, in 1945.