Rental prices, rates of return, capital aggregation and productivity : evidence from EU and US

With the increasing importance of investment in information and communication technology, methods for measuring the contribution of capital to growth have re-assumed centre-stage in recent growth accounting literature. The importance of using capital service growth rates rather than capital stock growth rates has long been advocated, and has become mainstream practice. However, the choice for a particular rate of return in the derivation of capital service prices is not straightforward and has barely been researched. Using four alternative rental price models based on both external and internal rates of return modelsthis article quantifies the differences in total factor productivity growth rates (TFPG) under different model assumptions. The differences in TFPG are also examined in terms of the inclusion of taxes and subsidies in the calculation of rental prices. Empirical analysis carried out for four EU countries and the US in 26 industries during 19792003 shows that the use of capital stock overestimates TFPG in most industries. Incorporation of taxes seems to have only modest effect. The magnitude of divergence generated by alternative rental price models-particularly between internal models- is quite low. The difference is seen to be relatively high between external rate of return models and internal rate of return models.