貿易成本、相對需求與生產區位選擇──創意商品之實證

TRADE COST, RELATIVE DEMAND AND THE CHOICE OF PRODUCTION LOCATION: AN EMPIRICAL STUDY OF TRADE IN CREATIVE GOODS

本國市場效果指在生產規模及貿易成本的取捨下，生產者群聚在需求較大的地區，進而使該地區成為主要出口來源地的現象。本研究從理論模型中導出新的重力迴歸式，增加「本國市場設定項」以體現區位選擇與貿易型態的關係。該項的重要性，從APEC創意商品貿易實證中充份顯現。省略該項，將使需求對出口的彈性之估計偏離重力方程式的預測。加入後，偏誤多被修正。這表示資料存在本國市場效果。且隨著距離縮短，本國市場效果更形強化。這些結果都是因考慮生產區位選擇影響貿易型態的傳導機制而獲得，顯然比過去未考慮該項因素的實證，更為可信。

Exporting producers, facing a trade-off between scale economies and trade costs, tend to cluster around the countries with larger demand, the so-called ‘home market effect’. Hsu et al. (2012) cast doubt on estimates in previous empirical studies on the effect using gravity regression. The potential bias comes from ignoring the important interactive effect of relative demand and trade cost on locational choice and thus on trade patterns. Using a dataset on the trade flow of creative goods from APEC countries, we find that after controlling for the interactive term, the estimated coefficients on the elasticity of demand are much corrected toward those predicted by theory. This constitutes more credible evidence for the existence of the home market effect.