消費外部性與經驗成長──兩部門模型的意涵

CONSUMPTION EXTERNALITIES AND ECONOMIC GROWTH A TWO SECTOR MODE

單部門成長模型強調消費外部性影響經濟體系的途徑是就業效果。因此在勞動供給外生決定的環境下，消費外部性並不會影響總體經濟表現。不同於既存文獻，本文設計一個納入消費外部性的兩部門成長模型並指出，消費外部性影響總體經濟體系的管道除了就業效果，還包括資源重分配效果。在固定規模報酬生產技術的假設下，不需要藉助就業效果，資源重分配效果會使得資本密集商品的消費外部性與經濟成長具有正向關係，但勞動密集商品的消費外部性與經濟成長率的關係則呈現不確定的狀態。另外，我們也討論了消費稅政策並發現兩部門架構下，資本密集商品的消費稅比較可能會傷害經濟成長表現。但勞動密集商品的消費稅對於經濟成長率的影響並不確定。

The effect of keeping up with the Joneses on macroeconomic performance has a long and controversial history. The existing literature usually adopts a one-sector growth model and indicates that the employment effect is the key factor in determining the effect of consumption externalities. This paper tries to incorporate consumption externalities into a two-sector endogenous growth model and finds that the sectoral re-allocation effect is also an important factor. Our results suggest that greater social aspirations in consumption may stimulate (deter) the rate of economic growth, provided that conspicuous goods are relatively capital-intensive (labor-intensive). We also find that the consumption tax in capitalintensive (labor-intensive) goods is more likely to deter (favor) the economic growth rate.