開放市場 - 經濟

最近唸了一篇論文
也寫了一些東西 想提出來給大家分享
這篇是講貿易成本和出口廠商數量以及生產力的關係

我想大家應該多多少少都有聽過"引力模型" 主要是講
兩國的距離以及兩國的產出是影響兩國貿易量的關鍵
站在經濟的角度上，大陸的產出不斷增加，我國與之
貿易的誘惑會越大，今天如果我國採取管制，那美加
或歐洲這些國家對我們而言很遠，貿易成本相對大陸
來的高，這篇剛好就是在研究貿易成本跟廠商以及廠
商生產力的關係。



Trade costs, firms and productivity
Andrew B. Bernard, J. Bradford Jensenb, Peter K. Schottca,JME
以下是心得區
1.Introduction
The potential link between trade liberalization and economic
growth is fundamental to both international and development
economics.

The route of research

First(macro): The first explores the country-level correlation
between openness and per capita GDP and asks whether
countries with low or falling trade barriers experience
higher income growth.

Second(micro) : investigates a microeconomic link between countries’
trade policies and their firms’productivity.

The goal of the paper
focuses on a microeconomic channel that stresses productivity
gains via the reallocation of economic activity across firms within
industries.( guided by the heterogeneous-firm models of Melitz (2003)
and Bernard et al. (2003))

What was Melitz and Bernard talking about?

(a)productivity differences across firms operating in encompassing
horizontally differentiated varieties.

(b)The existence of trade costs induces only the most productive firms
to self-select into export markets.

(c)As a result, when trade As a result, when tradecosts fall, industry
productivity rises both because low-productivity, non-exporting firms
exit and because high-productivity firms are able to expand through
exporting. The most productive non-exporters begin to export, and current
exporters, which are the highproductivity firms, expand their foreign
sales .

How can we test the implications of the heterogeneous-firm models ?

Methodology
examining whether the evolution of U.S. industry productivity is
related to the costs of engaging in international trade.

In practice
the linking of plant-level U.S. manufacturing data to industry-level
measures of tariff and transportation costs constructed from U.S.international trade statistics. We use these data to examine the effects
of changing trade costs on a variety of plant activities including survival
,entry into exporting, export growth and changes in productivity.

So what ?
(a)The industry productivity does indeed rise as trade costs fall.
(b We find that the probability of plant death is higher in industries
experiencing declining trade costs, as is the probability of a plant
successfully entering the export market and there are both winners
and losers within industries as a result of trade liberalization.
(c) we report evidence in favor of a relationship between falling trade
costs and increases in within-plant productivity declining trade costs
are associated with subsequent increases in productivity at surviving
plants.


以下是閒聊

最近跑去加拿大的網站看有沒有什
麼商品可跟台灣的商品套利，發現貿易成本真的是
很頭痛的東西，我也強烈懷疑老師選這篇給我們讀是
有特別目的的，因為我們以前的學長們老師給的都是
財務經濟方面(本科是財務經濟學)，似乎我們這屆是
例外唸貿易相關的文獻，不過這些都是後話了，選舉
到了，也希望大家少點政治，也祝大家學業順利
在此還是很高興大家撥空看我
的文章。



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