This paper is interesting and ambitious since it tries to provide both on the theoretical and empirical levels an integrated account of firm’s behaviour under the assumptions of an imperfectly competitive output market and of a putty-clay technology.

In my opinion subject to caution, if the author succeeds quite well at the theoretical level, the empirical results are more questionable.

One of the difficulties found in building an integrated model of firms’ behaviour is to take into account the different time horizons concerned by the firms’ enterprises.

The intertemporal characters of these decisions result from several factors: