Impact of Direct Income Payments on Productive Efficiency of Korean Rice Farms

This paper examines the impact of direct income payments on productive efficiency of Korean rice farms, using farm-level cross sectional data in 2006. For representation of efficiency and its determinants, this paper uses a model that estimates the deviations of farms from a translog distance function and the determinants of these deviations. This paper especially estimates a stochastic frontier production function to explain deviations from best-practice productivity with a two-part error term including statistical noise from measurement error and technical inefficiency arising from farms not reaching the production frontier boundary. The empirical evidence finds that farms that get a higher share of direct payments in farm revenue are less efficient than others. This inefficiency is reduced by increases in farm size. Another result indicates that farms received greater direct payments on aggregate are more efficient than other farms since fixed payment, one part of rice direct payment, is tied to the amount of a farm's cropland that has been enrolled in programs, as well as yield histories.direct income payments, productive efficiency, stochastic frontier production function, Korea, Agribusiness, Agricultural and Food Policy, Crop Production/Industries,

Raising Skepticisms on the Feasibility of Algorithmic Tacit Collusion

Advances in artificial intelligence accelerate the digitization of pricing in various industry domains, from home appliances to hotels. At the same time, economic theories and legal cases claim that the advances benefit some players through synchronous algorithmic pricing, so-called Algorithmic Tacit Collusion (ATC). However, the previous studies rely on artificial intelligence’s broad collusion mechanisms in various pricing scenarios. The paper unravels the mixture of ATC problems by specifying the algorithmic pricing context in platform providers’ oligopoly and adjusting the underlying assumptions to the context. Our simulation of Iterative Prisoner’s Dilemma (IPD) games with various heterogeneous pricing algorithms show that ATC emerges in rare conditions (i.e., algorithm and information symmetries). Our findings suggest that understanding the technology and business architectures should precede deriving the theories of ATC and implementing the legal cases and policies of digitization for the next generation’s pricing

PERSPECTIVES OF WATER QUALITY IMPROVEMENT BY AQUATIC MACROPHYTES AS NUTRIENT SINK IN THE LAKE PALDANGHO, KOREA

Improvement of water quality by aquatic macrophytes was studied at the Lake Paldangho, a reservoir supplying the service water for 15 million inhabitants in the Capital of Korea. Annual production of aboveground of emergent plants having 1800 g DW/m² for Typha angustata and 1700g DW/m² for Zizania latifolia, are 15- to 30-folds as large as those of submersed plants having 110 g DW/m² for Ceratophyllum demersum and 60 g DW/m² for Hydrilla verticillata. Although concentrations of nitrogen and phosphorus in mg per g dry matter of emergent plants are small as a half of those of submersed ones, standing nutrients in g per m² of the former are 8- to 9-folds as large as that of the latter because of large production. Annual return of nutrients from the litters are also more in emergent plants than in submersed one. In the whole Lake the uptake amounts by macrophyte (sink) are 30.3 ton of nitrogen and 4.9 ton of phosphorus, and the return amounts from the litter (source) are 18.5 ton of nitrogen and 4.3 ton of phosphorus. Difference between the sink and the source, 11.8 ton for nitrogen and 0.6 ton for phosphorus, will remain in sediment of littoral zone. If aboveground of macrohytes are weeded out on time occurring the maximum production nutrients remaining will be reduced. To increase the annual production, repetitive harvesting of Zizania latifolia is effective.Article信州大学理学部付属諏訪臨湖実験所報告 7: 167-175(1991)departmental bulletin pape