I’ve had a couple conversations with graduate students in recent months about classifying industries or occupations by their tradability, so here’s a blog post reviewing some of the relevant literature.
A number of papers emphasize predictions that differ for tradable and non-tradable activities. Perhaps the most famous is Atif Mian and Amir Sufi’s Econometrica article showing that counties with a larger decline in housing net worth experienced a larger decline in non-tradable employment.
Mian and Sufi define industries’ tradability by two different means, one yielding a discrete measure and the other continuous variation:
The first method defines retail- and restaurant-related industries as non-tradable, and industries that show up in global trade data as tradable. Our second method is based on the idea that industries that rely on national demand will tend to be geographically concentrated, while industries relying on local demand will be more uniformly distributed. An industry’s geographical concentration index across the country therefore serves as an index of “tradability.”
Inferring tradability is hard. Since surveys of domestic transactions like the Commodity Flow Survey don’t gather data on the services sector, measures like “average shipment distance by industry” (Table 5a of the 2012 CFS) are only available for manufacturing, mining, and agricultural industries. Antoine Gervais and Brad Jensen have also pursued the idea of using industries’ geography concentration to reveal their tradability, allowing them to compare the level of trade costs in manufacturing and services. One shortcoming of this strategy is that the geographic concentration of economic activity likely reflects both sectoral variation in tradability and sectoral variation in the strength of agglomeration forces. That may be one reason that Mian and Sufi discretize the concentration measure, categorizing “the top and bottom quartile of industries by geographical concentration as tradable and non-tradable, respectively.”
We might also want to speak to the tradability of various occupations. Ariel Burstein, Gordon Hanson, Lin Tian, and Jonathan Vogel’s recent paper on the labor-market consequences of immigration varying with occupations’ tradability is a nice example. They use “the Blinder and Krueger (2013) measure of `offshorability’, which is based on professional coders’ assessments of the ease with which each occupation could be offshored” (p.20). When they look at industries (Appendix G), they use an approach similar to that of Mian and Sufi.
Are there other measure of tradability in the literature?
A Fine Theorem has a nice write-up of Dave Donaldson’s Railroads of the Raj. He’s put in more effort than I did when writing it up in 2009.
David Atkin and Dave Donaldson are presenting this paper tomorrow afternoon at the NBER summer institute:
This paper uses a newly collected dataset on the prices of narrowly defined goods across many dispersed locations within multiple developing countries to address the question, How large are the costs that separate households in developing countries from the global economy? Guided by a flexible model of oligopolistic intermediation with variable mark-ups, our analysis proceeds in four steps. first, we measure total intranational trade costs (ie marginal costs of trading plus mark-ups on trading) using price gaps over space within countries—but we do so only among pairs of locations that are actually trading a good by drawing on unique data on the location of production of each good. Second, we estimate, separately by location and commodity, the passthrough rate between the price at the location of production and the prices paid by inland consumers of the good. Our estimates imply that incomplete pass-through—and therefore, intermediaries’ market power—is a commonplace, and that pass-through is especially low in remote locations. Third, we argue that our estimates of total trade costs (Step 1) and pass-through rates (Step 2) are sufficient to infer the primitive effect of distance on the marginal costs of trading; after correcting for the fact that mark-ups vary systematically across space we find that marginal costs are affected by distance more strongly than typically estimated. finally, we show that, in our model, the estimated pass-through rate (Step 2) is a sufficient statistic to identify the shares of social surplus (ie the gains from trade) accruing to inland consumers, oligopolistic intermediaries, and deadweight loss; applying this result we find that intermediaries in remote locations capture a considerable share of the surplus created by intranational trade.
You can listen to a podcast of Donaldson presenting a much earlier version of this work from the International Growth Centre. He does a really nice job of summarizing the issues involved in inferring trade costs from price data.
Richard Florida says “While it’s commonly thought that globalization has put the world’s global cities on an increasingly level playing field, substantial differences in prices persist”:
What should leap to mind? Trade costs.
The biggest price gap (a ratio of 100) is for a good that is completely non-tradable and varies greatly in quality (bus fare is 7 cents in Mumbai and $7 in Oslo). A good of relatively uniform quality that is perishable varies quite a bit (Big Mac, from $2 in Shanhai to $6 in Oslo). A durable good with a high value-to-weight ratio, the iPad 2, exhibits less variation, a ratio of under two ($1058 in Buenos Aires and $548 in Bangkok). So it looks like trade costs are a pretty good explanation for nominal price differences.
That iPad gap may not be as large as it seems. You’ll want to adjust for taxes. The VAT is 21% in Argentina and 7% in Thailand.
How can there still be a ~$350 price difference when one can probably mail an iPad to most countries for less than a hundred bucks? Shouldn’t arbitrage drive price differences for identical products down to the shipping cost? Not so fast. It turns out it’s quite difficult to arbitrage iPads. Apple tracks its customers and doesn’t allow bulk purchases.
Why is gasoline, a very homogeneous and fungible commodity, $2 in Amsterdam but only 42 cents in Dubai? Taxes in the former and subsidies in the latter.
In short, these data are a lesson about trade costs. You’ll notice that Richard Florida didn’t title his post “why you should buy a bus ticket in Mumbai instead of Oslo”!
(Relatedly, price comparisons of personal services, as opposed to goods, suggest a lesson about global labor mobility. A one-hour Thai massage costs $6 in Bangkok and about $100 in New York City!)
An update on the Panama Canal expansion from the Economist that focuses on the west coast’s reaction:
But what can the California ports do? Floating cargo from Asia to the east coast by boat will always be cheaper, concedes Christopher Lytle, the executive director of the Port of Long Beach. But unloading in Long Beach and taking the train to New York can be faster by a week, he says. So California’s ports must compete on speed, which is increasingly important for time-sensitive goods such as fashion wear or consumer electronics. Let the lawn chairs go and keep the iPads, he reckons.
A lot must happen to keep that advantage in speed, however. One bottleneck is that short truck ride to the railway yard. Not only do the trucks account for much of the port’s air pollution (even though they are dramatically cleaner than just a decade ago), but they clog up stretches of the I-710 freeway, wasting precious time. One of the port’s plans is therefore to build a new, better and closer railway yard…
David Pettit, a lawyer at the National Resources Defence Council and one of those environmentalists who so frustrate Mr Baker, says that he fully understands the threat posed by the canal. But moving the railway yard to another community, and thus polluting it, is not the answer. Better, he says, to put the railway yard right on the docks. That would take up too much space, replies the port. The combatants have only until 2014 to work out their answer and build it.
Here’s how the World Development Report 2009 summarized a Peruvian trade-facilitation project:
BOX 8.9 Exporting by mail in Peru—connecting small producers to markets
In many countries small enterprises are often excluded from export chains because they operate in villages or small towns or do not have the needed information to export. In Peru a trade-facilitation program called “Easy Export” connects small producers to markets. The key to this program is the most basic of transport networks—the national postal service.
How does it work? An individual or firm takes a package to the nearest post office, which provides free packaging. The sender fills out an export declaration form, and the post office weighs the package and scans the export declaration form. The sender pays the fee for the type of service desired. Goods with values of $2,000 or less can be exported. The main benefit is that the exporter does not need to use a customs agent, logistics agent, or freight forwarder or to consolidate the merchandise; even the packaging is provided. Firms or individuals need only to go to a post office with a scale and a paper scanner and to use the Internet to complete the export declaration for the tax agency.
Has it made a difference? Within six months of inception, more than 300 firms shipped goods totaling more than $300,000. Most users are new exporters—microentrepreneurs and small firms, producing jewelry, alpaca and cotton garments, food supplements (natural products), cosmetics, wood art and crafts, shoes and leather, and processed food. And many of them are in the poorest areas of the country.