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on Information and Communication Technologies |
| By: | Andre Jungmittag (University of Wuppertal); Paul J.J. Welfens (University of Wuppertal and IZA Bonn) |
| Abstract: | In EU countries, opening up of telecommunications markets and regulations have helped to reduce the price of digital services which is an important quasi-input factor in all firms. Integrating the use of telecommunications in a macroeconomic production function is the analytical starting point for our interdependent analysis of output, use of telecommunications and employment. Based on unit root and co-integration analysis as well as an error correction three-equation model which are estimated simultaneously, we present results both on long run links and short run links between telecommunications, output and employment. Considering various scenarios suggests that a fall in the relative price of telecommunications can generate a cumulated employment increase of 760,000 within seven years in Germany. The institutional setup for regulating telecommunications could be improved in Germany and other EU countries. |
| Keywords: | telecommunications, employment, growth, knowledge society, regulation |
| JEL: | E0 L96 O0 |
| Date: | 2006–10 |
| URL: | http://d.repec.org/n?u=RePEc:iza:izadps:dp2379&r=ict |
| By: | Ke-Li Xu (Dept. of Economics, Yale University); Peter C.B. Phillips (Cowles Foundation, Yale University) |
| Abstract: | Stable autoregressive models of known finite order are considered with martingale differences errors scaled by an unknown nonparametric time-varying function generating heterogeneity. An important special case involves structural change in the error variance, but in most practical cases the pattern of variance change over time is unknown and may involve shifts at unknown discrete points in time, continuous evolution or combinations of the two. This paper develops kernel-based estimators of the residual variances and associated adaptive least squares (ALS) estimators of the autoregressive coefficients. These are shown to be asymptotically efficient, having the same limit distribution as the infeasible generalized least squares (GLS). Comparisons of the efficient procedure and the ordinary least squares (OLS) reveal that least squares can be extremely inefficient in some cases while nearly optimal in others. Simulations show that, when least squares work well, the adaptive estimators perform comparably well, whereas when least squares work poorly, major efficiency gains are achieved by the new estimators. |
| Keywords: | Adaptive estimation, Autoregression, Heterogeneity, Weighted regression |
| JEL: | C14 C22 |
| Date: | 2006–10 |
| URL: | http://d.repec.org/n?u=RePEc:cwl:cwldpp:1585&r=ict |