Comment on Chapters 3 and 4

  • E. R. de Regt


The two papers by Ansar et al. and by Muysken and van Zon (further referred to as AITU and MvZ respectively) extend existing putty-clay vintage labour demand models into different, though related, directions. AITU focus on long-run and short-run substitution possibilities between the production factors. The dual approach adopted allows the authors to test the often-used putty-clay, putty-putty or clay-clay production models against their maintained hypothesis of a putty-semi-putty model. The latter vintage model allows for both ex ante and ex post substitution possibilities, though the ex post substitution characteristics for each vintage are reduced by the ex ante choice of production technique. Nevertheless, for active vintages factor proportions are, among other things, influenced by actual factor prices.


Labour Productivity Capital Stock Technological Progress Labour Demand Demand Equation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. FUSS, M. A. (1977) ‘The Structure of Technology over Time: A Model for Testing the ‘Putty-Clay’ Hypothesis’, Econometrica, 45, pp. 1797–1821.CrossRefGoogle Scholar

Copyright information

© Joan Muysken and Chris de Neubourg 1989

Authors and Affiliations

  • E. R. de Regt

There are no affiliations available

Personalised recommendations