Successive markets constitute a natural framework to study the value chain. This chain is built through the technological linkage between markets where inputs and the corresponding outputs are produced. If goods pass through a chain of imperfectly competitive markets, in excess of the value markups are also added, at each step, to the costs. This thesis firstly proposes a unified framework to analyze competition in successive oligopolies. Analyzing and developing such a general framework forms a basis for the analysis of entry of new firms and of collusive agreements in the same market, like horizontal mergers, or through different markets, like vertical integration. The results bring new insights on equilibrium outcomes of both collusive agreements and entry of new firms.

Successive markets constitute a natural framework to study the value chain. This chain is built through the technological linkage between markets where inputs and the corresponding outputs are produced. If goods pass through a chain of imperfectly competitive markets, in excess of the value markups are also added, at each step, to the costs. This thesis firstly proposes a unified framework to analyze competition in successive oligopolies. Analyzing and developing such a general framework forms a basis for the analysis of entry of new firms and of collusive agreements in the same market, like horizontal mergers, or through different markets, like vertical integration. The results bring new insights on equilibrium outcomes of both collusive agreements and entry of new firms.