This thesis comprises an introduction and four distinct chapters. Its central theme is the role played by the allocation of asset ownership rights in motivating asset-specific investment, when contracts are incomplete. Chapter 1 considers the debt financing of an entrepreneurial project. To encourage asset-specific investment and loan repayment, debt structure should minimise both (voluntary) strategic default and liquidation following (unavoidable) liquidity default. Liquidation incentives are critical and shown to depend crucially on creditor characteristics. In general, borrowing from multiple creditors with contrasting attributes is found optimal. The benefits of borrowing from a creditor also undertaking project trade are explored. In Chapter 2 the relationship between asset ownership and investment specificity is examined. Asset control encourages efficient, asset-specific investment by owners. However, lock-in fears lead non-owners to choose widely applicable but less effective investment. The interactions between asset ownership, firms' technology choices and workers' investments are considered. In particular, it is found that the costs and benefits of individual integration decisions are sensitive to overall industry structure. The specificity framework is extended in Chapter 3 to model a retailer's product choice. Vertical merger encourages investment in integrated supply and foreclosure of non-integrated manufacturers. An anti-competitive as opposed to an efficiency interpretation depends delicately on the trade-off between the benefits of supplier-specific investment and multi-product retailing. Where retailers compete, it is shown that vertical integration implements effective competition-reducing differentiation strategies. In Chapter 4 vertical integration, through the incentive effects of asset ownership, is shown to amount to a specialisation decision. The attractions of encouraging investment in input as opposed to final good production depend on the effectiveness of investment at each manufacturing stage, and the scale benefits of input sales to generally rivalrous downstream firms. These benefits are sensitive to downstream competitive pressures, yielding a potentially non-monotonic relationship between competition and integration.