金子 文洋

奥本佳伸先生退職記念号欧文抄録: p.210

I criticize that a general consumption tax brings not only an inefficiency of the market equilibrium allocation but also a corruption of the government. The rate of a general consumption tax is equal to the gains to trade at the inefficient equilibrium allocation, which corresponds to the maximal rate of default allowed in an infinitesimal Pareto improving trade by consumers. It is by itself unobservable in the market, but the implementation of a general consumption tax makes it observable. Since the government is the sole economic agent that has an ability to execute complex trades outside the market which allow default, a general consumption tax makes an opportunity of seizure a common knowledge among relevant members of the government. By finding an infinitesimal Pareto improving trade in which the government can seize almost maximally, and extending it with keeping the drop in the rate of seizure minimum so as to force consumers only marginally improved, they can gain in utility significantly by the seizure. Such a trade can be constructed out of observables in the market and can be executed under the balanced budget by the government.欧文抄録: p.183

I show that a temporal credit-saving policy that promises to subsidize the payment of the leverage contract by a prespecified amount if the economy turns out to be bad do not improve the welfare of financial traders. The analysis is based on a 3-period general equilibrium model in which a bond and an equity are traded by risk-neutral traders with different beliefs, and leverage opportunuities are available. Itis assumed that, after the policy is implemented, the previous leveragecontract is adjusted according to its content. Under a condition on the variation of optimism among traders, the policy improves illusionary the welfare of traders since the tax to finance them cannot be foreseen. However, after the tax is levied in the final period, a group of bond holders is worse off. The resulting allocation is Pareto suboptimal.欧文抄録: p.121

This article is the first of the series in which the effect of temporalcredit-saving policies by the government on the economic welfare offinancial traders is analyzed.欧文抄録: p. 273

In this article, I prove that, using a simple principal-agent model of implicit labor contract without information asymmetry, the comparative statics of its Stackelberg-type equilibrium shows that the rational economic decision making by the farmer (the principal) and the laborers (the agent) in changing economic circumstances was the main force of institutional change in the rice cropping area of the Philippines. The key idea is to introduce an incentive wage scheme. Since the wage of agricultural work must be paid by new rice crops, the work on weeding cannot be paid immediately. This gives the employing farmer an incentive to devise a wage scheme on the harvesting work that is a nondecreasing function of the amount of the weeding work. By restricting the wage scheme to the concave class, I show that the optimal choice of the wage scheme by the farmer is either constant or linear with a positive slope. The former corresponds to the Hunusan, while the latter with the target amount of weeding work by the farmer equal to the maximum he needs corresponds to the Gama. The transition from Hunusan to Gama in the period of late 1960s to early 1970s is explained by the rapid technological innovation, which increases the amount of weeding work the farmer needs. The transition from Gama to New Hunusan in the period of late 1980s to early 1990s is explained by the rapid increase of the wage of daily-contract work in the urban industrial area. Several technical problems existed in the earlier version of this article are corrected.