The results show that,(1) Under observable contracts,suppliers horizontal merger will have adverse impact on customers,while the impact of retailers horizontal merger on customers depends on the degree of product substitution: if the degree of substitution is high,it will have favor.

Aimed at one-part linear observable contracts and unobservable(secret) contracts,the authors compare and analyze the effect of the increase of concentration of suppliers and retailers horizontal mergers on customers welfare.

A Research Review on Theories and Models of Firms Horizontal Mergers;

Horizontal Mergers of Firms with Decentralized Delegation in Differentiated Bertrand Oligopoly;

Review of Anti-monopoly on Horizontal Merger Control;

This paper introduces the development of M&A and its current progress in China,then makes an economic analysis on horizontal acquisition,deals with the problem of the optimal scale and the economic benefit assess of horizontal acquisition.

The results show the enterprises have more motive to carry out the strategy of vertical merger and integration in the product market with network externality.

Based on the upstream firms, this paper examines the competitive effects of vertical mergers in a successive duopolistic market structure with independent downstream demands and imperfect substitutional inputs.