Measuring Science: An Exploration
This paper examines available U.S. data on academic R&D expenditures and the number of papers published and the number of citations to these papers as possible measures of `output' of this enterprise. We look at these numbers for science and engineering as a whole, for 5 selected major fields, and at the individual university-field level. The published data in Science and Engineering Indicators imply sharply diminishing returns to academic R&D using published papers as a 'output' measure. These data are problematic. Using a newer set of data on papers and citations, based on an `expanding' set changes the picture drastically, eliminating seemingly diminishing returns but raising the question of why input prices of academic R&D are rising so much faster than either the GDP deflator or the implicit R&D deflator in industry. A production function analysis of such data indicates significant diminishing returns to `own' R&D, with the R&D coefficients hovering around 0.5 for estimates with paper numbers as the dependent variable and around 0.6 if total citations are used. When we substitute scientists and engineers in place of R&D as the right hand side variables, the coefficient on papers rises from 0.5 to 0.8, and the coefficient on citations rises from 0.6 to 0.9, indicating systematic measurement problems with R&D as the sole input into the production of scientific output. But allowing for individual university-field effects drives these numbers down below unity. Since in the aggregate both paper numbers and citations are growing as fast or faster than R&D, this can be seen as leaving a major, yet unmeasured role, for the contribution of spill- overs from other fields, other universities, and other countries.
|Date of creation:||Mar 1996|
|Date of revision:|
|Publication status:||published as in Proceedings of the National Academy of Sciences, vol. 93, pp.12664-12670 November 1996.|
|Contact details of provider:|| Postal: National Bureau of Economic Research, 1050 Massachusetts Avenue Cambridge, MA 02138, U.S.A.|
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- Zvi Griliches, 1958. "Research Costs and Social Returns: Hybrid Corn and Related Innovations," Journal of Political Economy, University of Chicago Press, vol. 66, pages 419.
- Jorgenson, D.W. & Fraumeni, B.M., 1991.
"The Output Of The Education Sector,"
Harvard Institute of Economic Research Working Papers
1543, Harvard - Institute of Economic Research.
- Paula E. Stephan, 1996.
"The Economics of Science,"
Journal of Economic Literature,
American Economic Association, vol. 34(3), pages 1199-1235, September.
- Griliches, Zvi, 1994.
"Productivity, R&D, and the Data Constraint,"
American Economic Review,
American Economic Association, vol. 84(1), pages 1-23, March.
- Pardey, Philip G., 1987.
"The Agricultural Knowledge Production Function: An Empirical Look,"
Evaluating Agricultural Research and Productivity, Proceedings of a Workshop, Atlanta, Georgia, January 29-30, 1987, Miscellaneous Publication 52
50022, University of Minnesota, Agricultural Experiment Station.
- Pardey, Philip G, 1989. "The Agricultural Knowledge Production Function: An Empirical Look," The Review of Economics and Statistics, MIT Press, vol. 71(3), pages 453-61, August.
- Mansfield, Edwin, 1991. "Academic research and industrial innovation," Research Policy, Elsevier, vol. 20(1), pages 1-12, February.
- Richard C. Levin & Alvin K. Klevorick & Richard R. Nelson & Sidney G. Winter, 1987. "Appropriating the Returns from Industrial Research and Development," Brookings Papers on Economic Activity, Economic Studies Program, The Brookings Institution, vol. 18(3), pages 783-832.
- Adams, James D, 1993.
"Science, R&D, and Invention Potential Recharge: U.S. Evidence,"
American Economic Review,
American Economic Association, vol. 83(2), pages 458-62, May.
- James D Adams, 1993. "Science, R&D, And Invention Potential Recharge: U.S. Evidence," Working Papers 93-2, Center for Economic Studies, U.S. Census Bureau.
- Rosenberg, Nathan & Nelson, Richard R., 1994. "American universities and technical advance in industry," Research Policy, Elsevier, vol. 23(3), pages 323-348, May.
- Richard Nelson, 1962. "The Link Between Science and Invention: The Case of the Transistor," NBER Chapters, in: The Rate and Direction of Inventive Activity: Economic and Social Factors, pages 549-584 National Bureau of Economic Research, Inc.
- Adams, James D, 1990. "Fundamental Stocks of Knowledge and Productivity Growth," Journal of Political Economy, University of Chicago Press, vol. 98(4), pages 673-702, August.
- Weisbrod, Burton A, 1971. "Costs and Benefits of Medical Research: A Case Study of Poliomyelitis," Journal of Political Economy, University of Chicago Press, vol. 79(3), pages 527-44, May-June.
- Richard C. Levin & Alvin K. Klevorick & Richard R. Nelson & Sidney G. Winter, 1988. "Appropriating the Returns from Industrial R&D," Cowles Foundation Discussion Papers 862, Cowles Foundation for Research in Economics, Yale University.
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