清水 隆則

<p>汚染排出枠の削減が及ぼす効果に関する分析は, 重要で興味深い。Chao and Sgro（2008）は, 非貿易財を含む2財3要素小国開放経済モデルを構築し, 最適汚染税に関する分析を行ったが, 排出枠の変化が厚生や財生産, 要素報酬に及ぼす効果を十分分析しなかった。本稿では, コブ＝ダグラス型効用関数の下で, 排出枠の減少が交易条件に及ぼす効果を分析し, それにより経済厚生や財生産, 要素報酬に及ぼす効果を, 間接効果を含めて包括的に検討する。</p>

This paper studies the effects of labor supply on relative wages in a dynamic North-South model of trade. Lai (1995) - a generalization of the Grossman and Helpman (1991a,b, ch. 11) models - showed that the relative wage of skilled (unskilled) labor in a region is positively (negatively) related to the supply of skilled (unskilled) labor in that region. These surprising results depend crucially on the specification of the functional form of the Southern imitation activity. We will show that these results (except for the relative wage of unskilled labor in Lai) are reversed in the case where the productivity of imitation depends only on the number of products the North manufactures. © 2008 The Authors; Journal compilation © 2008 Blackwell Publishing Ltd.

This paper analyses the local stability of the steady state of the generalized Lai (1995) model, i.e. the Shimizu and Okamoto (2004) model. Lai is a modified version of Grossman and Helpman (1991a, 1991b: Ch. 11) by assuming that there are two types of labour: skilled and unskilled labours. Shimizu and Okamoto (2004) generalize the Lai model by assuming that Southern knowledge stock depends not only on Southern cumulative experience but also on the number of products the North manufactures. This paper shows that the stability of steady state in the generalized Lai model has the saddle point property. Thus, this paper also establishes the stability of the Grossman and Helpman (1991a, 1991b: Ch. 11) model. © 2005 Taylor & Francis.

In this paper we investigate the effect of labor supply on various distributions of income in a North-South trade model with skilled and unskilled labor. Modifying Lai (1995) 's model by allowing external effects of imitation activity, we have shown there exists the critical value of parameter a below which all the results Lai has shown, especially, an increase in skilled labor supply raises its steadystate relative wage if the elasticity of substitution between goods is sufficiently large hold. And above the critical value, one of the results is reversed, that is, an increase in skilled labor supply reduces its steady-state relative wage. In both cases, nevertheless, North's effort to increase in skilled labor supply can increase the steady-state rate of innovation.