5Barro, Robert J. and Lee, J. “International Data on Educational Attainment: Updata and Implications. ” CID Working Paper, April 2000, No. 42.
6Christiansen, Lone E. “Do Technology Shocks Lead to Productivity Slowdown? Evidence form Paten Data. ” Unpub. Ph.D. Dissertation, University of California, san Diego, 2007.
7De Long, J. and Summers, L. “Equipment Investment and Economic Growth. ” Quarterly Journal of Economics, 1991,106, pp. 445 -502.
8Cordon, R. The Measurement of Durable Goods Prices. Chicago: University of Chicago Press, 1990.
9Greenwood, J. ; Hercowitz, Z. and Kruscll, P. “Long-run Implications of Investment -Specific Technological Change. ” The American Economic Review, 1997, 87, pp. 342-362.
10Griliches, Zvi. “Patent Statistics as Economics Indicators: A Survey. ” Journal of economic Literature, 1990, 28, pp, 1661 -1707.