Thursday, August 06, 2009

Dave Donaldson, the railroads of the British Raj, and infrastucture policy

He tests six propositions:


1. Inter-district price differences are equal to trade costs (in special cases): That is, if a com-
modity can be made in only one district (the ‘origin’) but is consumed in other districts (‘des-
tinations’), then that commodity’s origin-destination price difference is equal to its origin-
destination trade cost. I use this result to infer trade costs (which researchers never fully
observe) by exploiting widely-traded commodities that could only be made in one district.
Using inter-district price differentials, along with a graph theory algorithm embedded in a
non-linear least squares routine, I estimate the trade cost parameters governing traders’ en-
dogenous route decisions on a network of roads, rivers, coasts and railroads. This is a novel
method for inferring trade costs in networked settings. My resulting parameter estimates
reveal that railroads significantly reduced the cost of trading in India.

2. Bilateral trade flows take the ‘gravity equation’ form: That is, holding constant exporter- and
importer-specific effects, bilateral trade costs reduce bilateral trade flows. I find that railroad-
driven reductions in trade costs (estimated in Step 1) increase bilateral trade flows, and show
that the parameters estimated from the gravity equation identify my model.

3. Railroads reduce the responsiveness of prices to local productivity shocks: That is, a district’s
prices are less responsive to its own productivity shocks when it is connected to the railroad
network; however, a district’s prices are more responsive to any other district’s productivity
shocks when these two districts are connected by a railroad line. I find empirical support
for both of these predictions. Specifically, in a novel test for market integration, I find
that railroads caused a dramatic reduction in the responsiveness of prices to local rainfall
shocks, reducing responsiveness to almost zero (even when focusing purely on rainfall vari-
ation across crops, within a district and year). This implies that railroads brought India’s
district economies close to the small open economy limit where local conditions have no effect
on local prices. I also find that a district’s rainfall shocks affect prices in neighboring districts
to which it is connected by the railroad network (to a weak but statistically significant extent).

4. Railroads increase real income levels: That is, when a district is connected to the railroad
network its real income rises; however, improvements in the railroad network that by-pass
a district reduce the district’s real income (a negative spillover effect). Empirically, I find
that own-railroad access raises real income by 18 percent, but a neighbor’s access reduces
real income by 4 percent. However, these are reduced-form estimates that could be due to a
number of mechanisms. A key goal of Step 6 is to assess how much of the reduced-form effect of
railroads can be attributed to gains from trade due to the trade cost reductions found in Step 1.

5. Railroads decrease real income volatility: When a district is connected to the railroad network,
its real income is less responsive to stochastic productivity shocks in the district (which reduces
volatility). Empirically, I find that railroads reduced the responsiveness of real agricultural
income to local rainfall, which suggests a second welfare benefit of transportation infrastruc-
ture (in addition to that found in Step 4) that has not, to my knowledge, been demonstrated
empirically before. However, as with the results in Step 4, a number of mechanisms could
underpin this reduced-form result.

6. There exists a sufficient statistic for the welfare gains from railroads: That is, despite the com-
plexity of the model’s general equilibrium relationships, the impact of the railroad network on
welfare in a district is captured by one variable: the share of that district’s expenditure that
it sources from itself. A prediction similar to this appears in a wide range of trade models
but has not, to my knowledge, been tested before.3 I test this prediction by regressing real
income on this sufficient statistic (as calculated using the model estimated in Steps 1 and 2)
alongside the regressors from Steps 4 and 5 (which capture the reduced-form impact of rail-
roads).4 When I do this, the reduced-form coefficients on railroad access estimated in Steps
4 and 5 fall to a level that is close to zero. This finding provides support for prediction 6 of
the model and suggests that decreased trade costs account for virtually all of the real income
impacts of the Indian railroad network.



Beyond his findings, he uses clever empirical strategy to show that his results are not spurious. In particular, he tests his propositions for areas where railroads were planned put not executed, and finds that they do not get the perceived benefits of the railroads.

While the impact of infrastructure development in the US now would be less spectacular than railroad development in the Indian Raj, Donaldson's paper still has important implications, particularly about the development of freight transport systems and intermodal transportation. The paper is also a terrific read.

4 comments:

Anonymous said...

簡善琳瑜珈補習班創辦人簡善琳老師,在三十幾年前瑜珈風氣尚未盛行的少女時代即對它產生濃厚興趣少時體質贏弱敏感也因瑜伽而獲得顯著改善,所以立志貢獻所學,藉由瑜珈來達成幫助國人身體健康的願望。高雄瑜珈中簡善琳瑜伽養生會館除了硬體設備在會館環境上建立最精緻、最優質的多功能複式場所外,為避免其他瑜珈教室之師資情況(即投入教學工作則無力再學習進修之窘境),對於師資的培訓與要求更是不遺餘力,所有師資不分資深資淺每個月都要接受新的瑜伽課程訓練,期盼與國際接軌,隨時給予學員最新的資訊與知識。針對初學者教授九大關節操、拜日式、基本功法、淨脈呼吸法等,溫和而緩慢的瑜珈,透過簡單的延展動作及呼吸按摩身體各部位的經脈,奠定初學者學習瑜伽的基礎。會館裡有初級瑜伽、整體瑜伽、哈達瑜伽、養生瑜伽、有氧瑜伽、塑身瑜伽、氣功瑜伽、瑜伽提斯、Ashtanga、孕婦瑜伽、進階瑜伽、體位法瑜伽…等數十項豐富瑜伽課程提供選擇。

Anonymous said...

網路行銷
網路行銷
網路行銷
seo
seo
seo

Anonymous said...

Michael Jackson(麥可傑克森)你永遠是我的最愛^^
Michael Jackson,麥可傑克森

Michael Jackson,麥可傑克森

Michael Jackson,麥可傑克森

瑜珈,看護,旅遊

保健,蛋糕,服飾

網路,資訊,花園

法拍屋,隔熱紙

達人,精品,整形

科技,天空,飛翔

蝸牛,不孕,汽車

gaohui said...

Unconventional women don't ed hardy often fit into more ed hardy shoes conventional sizes. Instead, they are ed hardy clothing faced with the challenge of finding comfortable ed hardy clothes and stylish plus size women's clothing. By and large, most ed hardy store store refuse to stock sizes in ed hardy Bikini excess of a size 14 ed hardy swimsuits or 16. This means they have ed hardy Caps to find the clothes they need in specialty buy ed hardy store that can be very expensive. What then ed hardy swimwear is a plus size ed hardy sale woman to do? She has to do ed hardy glasses her research and find the cheap ed hardy places, both online and Christian audigier off, that will accommodate her wardrobe.