We are grateful to our colleagues at the Federal Planning Bureau and to staff at the National Accounts Division of the National Bank of Belgium for their comments and suggestions. We also like to thank Marleen Keytsman for her help in preparing the document. All remaining errors are ours.

In this paper, a methodology is proposed for the construction of ICT investment and capital stocks in Belgium. The series are obtained in nominal and in real terms and at macroeconomic as well as sector level. The ICT assets distinguished are IT equipment and communications equipment, leaving software out of the analysis. After calculation of investment expenditure on both assets, the expenditure is transformed into quality-adjusted volume terms by means of harmonised price indices derived from appropriate U.S. indices. Productive capital stocks are calculated by means of the perpetual inventory method, and rental prices of the ICT capital services are obtained as well.