Lotka, Alfred James  (1880 - 1949), USA


Alfred Lotka, chemist, demographer, ecologist and mathematician, was born in Lviv (Lemberg), at that time situated in Austria, now in Ukraine. He came to the United States in 1902 and wrote a number of theoretical articles on chemical oscillations during the early decades of the twentieth century, and authored a book on theoretical biology (1925). He is best known for the predator-prey model he proposed, at the same time but independent from Volterra (the Lotka-Volterra model, still the basis of many models used in the analysis of population dynamics). He then left (academic) science and spent the majority of his working life at an insurance company (Metropolitan Life). In that capacity he became president of the PAA (the Population Association of America).


The article that made him famous as a bibliometrician (avant la lettre) is just a footnote in his oeuvre. He showed that the number of authors with n publications in a bibliography is described by a power law of the form C/na, where C is a constant. The exponent  a is often close to 2. Rewriting this equation as a statistical distribution (so that the sum over all n becomes 1), he showed that in the case that a is exactly equal to two, C must be   6/(pi), or approximately 0.61. This means that if a bibliography can be described by Lotka's square law, approximately 61% of all authors have contributed just one article to this bibliography.


Lotka A.J. (1926). The frequency distribution of scientific productivity. Journal of the Washington Academy of Sciences, 16: 317-323.

Lotka, A. J. (1925). Elements of physical biology. Williams and Wilkins, Baltimore. [Reprinted in 1956: Elements of mathematical biology. Dover Publications, Inc., New York, New York].


See also my Time Table of Bibliometrics

and a program to fit Lotka's law.


Ronald Rousseau:


Highly cited researcher (2014) 


Doctoraat 022

Dilruba Mahbuba (Ruba) and her doctoral jury: December 17, 2012

Profs. Colpaert, Engels, Nyssen, Delsaerdt, dr. Mahbuba and me