Phil. Trans. R. Soc. A (2010) 368, 5707–5719 doi:10.1098/rsta.2010.0284 Complex dynamics of our economic life on different scales: insights from search engine query data BY TOBIAS PREIS 1,2,3,∗ ,DANIEL REITH 3 AND H. EUGENE STANLEY 1 1 Center for Polymer Studies, Department of Physics, 590 Commonwealth Avenue, Boston, MA 02215, USA 2 Artemis Capital Asset Management GmbH, Gartenstrasse 14, 65558 Holzheim, Germany 3 Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany Search engine query data deliver insight into the behaviour of individuals who are the smallest possible scale of our economic life. Individuals are submitting several hundred million search engine queries around the world each day. We study weekly search volume data for various search terms from 2004 to 2010 that are offered by the search engine Google for scientific use, providing information about our economic life on an aggregated collective level. We ask the question whether there is a link between search volume data and financial market fluctuations on a weekly time scale. Both collective ‘swarm intelligence’ of Internet users and the group of financial market participants can be regarded as a complex system of many interacting subunits that react quickly to external changes. We find clear evidence that weekly transaction volumes of S&P 500 companies are correlated with weekly search volume of corresponding company names. Furthermore, we apply a recently introduced method for quantifying complex correlations in time series with which we find a clear tendency that search volume time series and transaction volume time series show recurring patterns. Keywords: econophysics; cross correlations; autocorrelations; financial markets; search engine queries; pattern recognition 1. Introduction Econophysics research—econophysics forms the interdisciplinary interface between the two disciplines economics 1 and physics 2 —has been addressing a key question of interest in the subfield of financial markets: quantifying and 1 Ancient Greek: oı ’conomí a—management. 2 Ancient Greek: 4ysıch ´ t3 ´cnh—art of handling nature. ∗ Author for correspondence (mail@tobiaspreis.de). Electronic supplementary material is available at http://dx.doi.org/10.1098/rsta.2010.0284 or via http://rsta.royalsocietypublishing.org. One contribution of 14 to a Theme Issue ‘Complex dynamics of life at different scales: from genomic to global environmental issues’. This journal is © 2010 The Royal Society 5707