. / Corporate acquisitions are classified as part of “the market for corporate control” in which management teams are facing constant competition from other management teams. If the team that currently controls a company is not maximizing the value of the company’s assets, then an acquisition will likely occur and increase the value of the company by replacing its poor managers with good managers. This dissertation focus on two issues on mergers, the first compares the strategy between mergers and joint ventures. The second investigate how much liquidity should the acquirer preserve and what is the equilibrium price of the acquired firm in considering the merger strategy. Drawing upon the incomplete contract theory, I examine the criterion of the strategic choice between joint ventures (JVs) and mergers when two firms contemplate vertical integration. The model reaches the following conclusions: (1) some ownership provision to the acquired company after the mergers may prove to be more lucrative to the acquirer than 100% takeover; (2) given the same equity share arrangement for JVs and mergers I conclude that these two firms should choose to merge or be merged rather than JVs; (3) I derive the optimal equity share arrangement in both JVs and mergers when ownership provision is considered as a strategic means. In addition, I also compare the welfare and effort of both companies in JVs and mergers under symmetric cost structures, and find that mergers would provide greater social efficiency and welfare than 50-50 JVs when the acquirer’s equity share is between 30% and 65%. Firms are concerned that they may in the future be deprived of the funds that would enable them to take advantage of exciting growth prospects, strengthen existing investments or simply stay alive. I specifically examine a firm’s liquidity need in order to grasp any future opportunity of mergers and acquisitions. However, a firm’s manager (borrower) can shed his interim wrongdoings (misbehavior) under the pretext of further financial need for mergers and acquisitions because he knows that he can easily raise sufficient cash from lenders to cover any adverse shock. My study derives the conditions that when this soft-budget-constraint (SBC) problem will occur. It happens when the interim income is small. Moreover, I analyze how the purchase price of acquisition is affected by this soft-budget-constraint syndrome. If there is SBC problem, the acquisition price will be raised by the investors when the interim income is small. Besides, a firm with severe moral hazard problem will be merely able to offer a smaller purchase price for the acquisition. On the contrast, a firm with a stronger balance sheet will be able to secure a greater credit line and offer a more attractive price for the acquisition. The empirical study of U.S. firms during 1988 to 2006 supports my conclusions.