De macro-economische impact van ICT : economische trendgroei,conjunctuurcyclus en NAIRU [ Working Paper 02-03 - 03/03/2003]

First, the long-run impact of ict on macroeconomic growth has been the subject of many studies. In this literature, ict may positively affect economic growth by increasing labour productivity gains. Labour productivity growth may accelerate thanks to fast technical progress in the ict producing sectors, and thanks to the rapid accumulation of ict capital in the rest of the economy that results from the ensuing price declines of ict capital goods. More controversially, the diffusion of ict may also stimulate total factor productivity growth. Through these channels, ict can constitute a major stimulus for long-run productivity growth, as has been the case in the United States. The available evidence for Belgium suggests that, although labour productivity growth did not accelerate in the late 1990s, the adoption of these technologies by Belgian firms has led the growth contribution of ict capital to nearly double between the first and second half of the 1990s.

Second, ict may affect the cyclical economic growth around its trend. The impact the adoption of ict may have on the business cycle runs through at least two channels. Through the first channel, ict help to improve firms' inventory control. Just-in-time inventory control systems have led to a stabilisation of inventory investment, a small but very volatile component of aggregate demand. The second channel runs through gross investment of the business sector, another volatile component of aggregate demand. This channel has opposing effects, however: on the one hand ict increases gross investment because ict capital goods are characterised by large depreciation rates. On the other hand this fast depreciation may reduce the volatility of gross investment, as it allows adjusting investment plans faster after an economic shock. The direction of the overall effect is an empirical question.

Third, the possible impact of the increasing use of ict on the nairu is considered. The nairu is the unemployment rate consistent with stable inflation, and forms an important part of business cycle theory. The diffusion of ict may affect the nairu through three channels. Firstly, the nairu may temporarily fall if productivity growth accelerates but real wage claims adjust only gradually. Secondly, it may rise as a result of the asymmetric effects of increasing ict use on the unemployment of skilled and unskilled workers. Finally, the nairu may vary as a result of changes in the job matching technology. Although in the United States the combination of accelerated productivity growth and inert aspiration wages may have been of overriding importance, in Belgium the pernicious impact of ict on low-skilled workers may dominate the overall effect of ict on the nairu. However, this remains again a challenging empirical question.