Arnold, Lutz G. and Kornprobst, Wolfgang
The Dynamics of the Romer R&D Growth Model with Quality Upgrading.
Regensburger Diskussionsbeiträge zur Wirtschaftswissenschaft 413,
Other URL: http://www.opus-bayern.de/uni-regensburg/volltexte/2006/673/
This paper replaces increasing product variety with quality upgrading in the Romer (1990) model. We show that the range of parameters for which a steady state exists can be divided into two subspaces with well-behaved comparative statics and saddle-point dynamics in one subspace, but with “perverse” comparative-statics properties and either equilibrium indeterminacy or instability in the other subspace. In the latter subspace, a parameter change possibly leads to a Hopf bifurcation. Using a theorem in Arnold (in press), these results for the closed economy can also be used to characterize the dynamics of the M-country open-economy version of the model.