Japan's postal savings used mail network to reach rural savers

In the 1870s, commercial banks in Japan concentrated in cities and had no economic reason to build a branch in every small town and village -- the deposits any one rural branch could gather were too small to justify the fixed cost of staffing and running it. Ordinary rural households were left with no safe place to keep savings beyond cash at home, exposing them to theft and giving them no return, while the young Meiji state also badly needed a way to draw idle household cash into the formal financial system.

Japan's new postal service, however, already had exactly the physical reach a savings bank would need: a network of post offices and daily mail routes extending into towns and villages no commercial bank would ever open a branch in, built and paid for to carry mail rather than money. The infrastructure problem that made rural banking uneconomic on its own -- reaching thousands of small, scattered communities on a daily basis -- had already been solved for an entirely different purpose.