The effects of partially cooperating firms are examined in N-firm oligopolies. The Herfindahl-Hirschmann Index is assumed to detect the violation of the antitrust regulation by the firms, and based on this assumption a piece-wise differentiable dynamic system can be developed. The firms stop...

This study reconsiders a duopoly model with advertisement introduced earlier by Ahmed, Agiza and Hassan [1999]. It demonstrates three major findings. The first is that the model can be destabilized via either flip bifurcation or Hopf bifurcation. The second is that a half-pitchfork bifurcation...