Luís A. Nunes Amaral

co-Director, Northwestern Institute on Complex Systems
Professor of Chemical & Biological Engineering
Professor of Physics & Astronomy (by courtesy)
Professor of Medicine (by courtesy)

Chemical & Biological Engineering
2145 Sheridan Road (Room E136)
EvanstonIL 60208US
Phone: (847) 491-7850


We analyze the fluctuations in the gross domestic product (GDP) of 152 countries for the period 1950-1992. We find that (i) the distribution of annual growth rates for countries of a given GDP decays with "fatter" tails than for a Gaussian, and (ii) the width of the distribution scales as a power law of GDP with a scaling exponent beta approximate to 0.15. Both findings are in surprising agreement with results on firm growth. These results are consistent with the hypothesis that the evolution of organizations with complex structure is governed by similar growth mechanisms.