要素稅率差異對小型開放經濟均衡路徑未定之影響分析

AN ANALYSIS OF THE EFFECTS OF ASYMMETRIC FACTOR TAXATION ON THE INDETERMINACY OF THE SMALL OPEN ECONOMY

本文之重點為分析小型開放經濟出現均衡路徑未定（indeterminacy）的可能情況。在產業生產力為固定規模報酬的兩部門小型開放經濟體系設定下，相較於文獻上所指出的：若產業內存在部門別的生產外部性或是不對稱的要素稅率，則動態體系可能存在均衡路徑未定的情況。本文則是證明，若部門別的生產外部性及不對稱的要素稅率同時改變私人最適決策時，則私人最適決策予社會最適決策將會回復皆是以資本密集的方式生產非貿易資本財或是貿易財，此時經濟體系之動態調整將存在穩定的馬鞍路徑。透過本文的分析，可得出小型開放經濟之動態調整體系出現均衡路徑未定、均衡路徑確定、及發散的個別條件。此外，本文發現，生產外部性及要素稅率差異造成私人與社會規模報酬不一致乃是體系是否均衡路徑未定的主因，小型開放經濟的設定使得均衡路徑未定在較寬鬆的參數條件下出現，勞動供給內生不會造成均衡路徑未定，但會使要素稅率差異對於恆定狀態的影響加大。

This paper analyzes the possible circumstances of indeterminacy and determinacy for a two-sector small open economy with social constant return to scale technologies. In comparison with the other papers which show that the indeterminacy will happen if there exist sector-specific externalities or asymmetric factor taxation respectively, this paper shows that the indeterminacy will not happen if these two external forces exist simultaneously and alter the private optimal decision to the same direction. Under this circumstance, the economy will produce the traded or non-traded goods in a capital-intensive way and there exists a unique saddle path for the equilibrium dynamics. In addition, this paper investigates the source factors of indeterminacy among capital mobility, endogenous labor supply, sector　specific externalities and asymmetric factor taxation. The conclusion is that sector-specific externalities and asymmetric factor taxation are the key contributors of indeterminacy, while capital mobility makes indeterminacy easier to emerge. The endogenous labor supply will not cause the indeterminacy, but it will enlarge the effect of asymmetric factor taxation on the steady state value of the price and capital stock.