Using an array of indicators, each of which
represents an aspect of knowledge, as independent variables in cross-section regressions that span 92 countries for the period 1960 to 2000, the authors show that knowledge is a significant determinant of long- term economic growth.
Geography
Link
http://info.worldbank.org/etools/docs/library/117333/37702_wps3366.pdf#search=%22Knowledge%20and%20Development%3A%20A%20Cross-Section%20Approach%22