Job Matching under Constraints

Studying job matching in a Kelso-Crawford framework, we consider arbitrary constraints imposed on sets of doctors that a hospital can hire. We characterize all constraints that preserve the substitutes condition (for all revenue functions that satisfy the substitutes condition), a critical condition on hospitals’ revenue functions for well-behaved competitive equilibria. A constraint preserves the substitutes condition if and only if it is a “generalized interval constraint,” which specifies the minimum and maximum numbers of hired doctors, forces some hires, and forbids others. Additionally, “generalized polyhedral constraints” are precisely those that preserve the substitutes condition for all “group separable” revenue functions. (JEL C78, D47, I11, J23, J41, J44)

Study on Coordination and Optimization of Contract Farming Supply Chain Based on Uncertain Conditions

As the transaction subject of contract farming, agricultural products are featured with a long production cycle and a short sales cycle, just like other perishable commodities. In the process of executing a contract, both the company and the farmer are running the risk of great uncertainty. This paper studies the coordination of agricultural supply chain in terms of the uncertainty of agricultural output and market demand. First of all, the random output volatility factor and the market demand volatility factor as two random variables are used to represent the uncertainty of the agricultural output and market demand, and revenue functions are set up, respectively, for the company and the farmer with the objective of maximizing expected returns. The theoretical derivation of these revenue functions proves that there is an optimal targeted yield in a centralized decision-making supply chain system and a single optimal solution that maximizes farmers’ revenue can be obtained in a decentralized one, but the centralized decision-making supply chain is superior to the decentralized and uncoordinated counterpart for overall benefit. Secondly, a revenue-sharing-plus-margin contract mechanism is proposed to coordinate income distribution between the two parties of the supply chain through the revenue-sharing coefficient and margin. Thirdly, calculation examples are given and solved by MATLAB based on the assumption that both the agricultural output volatility factor and the market demand volatility factor are uniformly distributed, and the theory and result are then verified consistently. Finally, the numerical analysis of the coordination mechanism of the revenue-sharing coefficient and the margin on both sides of the supply chain provides an optimal value range so that Pareto improvement on the company’s and the farmers’ income can be achieved.

Traders’ market power along Indonesian rubber value chains

Purpose While traders of agricultural products are known to often exercise market power, this power has rarely been quantified for developing countries. The paper aims to discuss this issue. Design/methodology/approach In order to derive a measure, the authors estimate the traders’ revenue functions and calculate the marginal value products directly from them. The authors subsequently find the determinants affecting their individual market power. Findings Results show that market power at the traders’ level exists and is substantial. This market power is amplified in situations of extreme remoteness, and weakens with increasing market size. Originality/value An exceptional data set with detailed information on the business practices of rubber traders in Jambi, Indonesia is employed with an innovative methodology to directly estimate revenue functions.