In this paper we develop and apply a general imperfect competition model to evaluate returns to a cost-reducing innovation. Most related work has applied models of perfect competition. Results demonstrate that welfare estimates derived from a model of perfect competition may be seriously distorted when the relevant market is imperfectly competitive. Application to mechanical harvesting of processing tomatoes in Taiwan reveals the potential for significant benefits to adoption of mechanical harvesting in Taiwan. However, farmers' incentives to adopt the harvester are attenuated because total benefits are reduced by oligopsony power in tomato procurement, and imperfectly competitive processors will capture a large share of the benefits that remain. Copyright 1996, Oxford University Press.

Researchers have often attributed the farm-wholesale price spread, after adjusting for marketing costs, as compensation for marketing firms' risk bearing. However, price spreads in excess of marketing costs can also be due to marketing firms' exercise of market power. In settings where both imperfect competition and marketer risk aversion are plausible, a modeling framework must be sufficiently general to accommodate both types of behavior. This article develops and estimates such a model in the context of fresh produce marketing and develops the implications for analysis of supply-control programs. The model is applied to the production and marketing of Chinese cabbage in Taiwan and specifically to the analysis of supply-control programs implemented in this industry by the Taiwanese government. The empirical results provide little support for the hypothesis that marketing firms exhibit risk averse behavior, but they do show that marketing firms exercise oligopsony power in procurement of the product from farmers, and that this power is positively related to the quantity supplied in each market period. This provides a heretofore unexplored impetus for supply controls intended to raise producer incomes. However, such controls are also rendered less effective by imperfect competition because marketing firms capture part of the benefits from supply reduction. Copyright 2006 International Association of Agricultural Economics.