I’m working on a major new project measuring market integration and food markets in tropical Africa and Southeast Asian in the colonial period, and in particular on the integration of grain and salt markets in French West Africa. Though a great deal has been written both about railways and their impact on the one hand and local trade on the other, there is still a lot of historiographical blanks on the question of the impact of the construction of colonial railways on local product markets. One question I am trying to answer is: how geographically wide were grain markets in Africa? The best way to answer this is to study the behaviour of prices over time, and that’s why I’m gathering as many grain prices as I can, but one interesting metric of trade distance can be gained by exploiting published railway statistics. These will often give tonnage (how much stuff) and kilometric tonnage (how much stuff for what distance). Dividing kilometric tonnage by tonnage gives a measure of the average distance travelled by a ton of produce. Usually, published statistics in sources like the Bulletin mensuel de l’Agence économique de l’Afrique occidentale française give only the aggregate kilometric tonnage for all products, but fortunately, for a few months in 1923-4, we are given kilometric tonnage by product for a number of African railways. (I suspect there are more detailed product-level statistics in the archives, and that’s on my list for my next trip early next year).
As a glimpse, though, the published statistics produce an interesting hierarchy of goods—one that largely accords with what we might have guessed about the spatial nature of trade by product. Of course, lines were of differing lengths, so I’ve also calculated the average distance travelled as a percentage of the total length of the line. Maize, for example, seems to have been transported relatively short distances — 44 km on the Chemin de fer de la Côte d’Ivoire, between Abidjan and Bouaké, and 94km on the Central Dahomey line between Cotonou and Savé, especially compared with long-distance traded goods like salt—141km on average on the Central Dahomey and 252km on average on the Côte d’Ivoire line.
|Railway line||Good||Average travelled||% of total line|
|Central Dahomey||Maize||94 km||36%|
|Palm oil||72 km||23%|
|Côte d’Ivoire||Bananas||87 km||28%|
|Kola nuts||129 km||41%|
|Palm oil||50 km||16%|
|East Dahomey||Maize||41 km||51%|
|Palm oil||21 km||26%|
|Kayes–Niger||Kola nuts||401 km||73%|
|Shea butter||288 km||52%|
|Heating wood||80 km||15%|