> The Universal Postal Union set up a fee so richer countries would pay more to have their international mail delivered than countries with developing economies.

> "The central idea is that any citizen or business should be able to send mail packages through the Global Postal Network to any destination," said Schoorl.

> At the time, China was considered a country with a developing economy, meaning the country would be charged less for international mail than other countries. And that went unchanged for decades.

> As e-commerce took off in the 2010s, China found itself with a major competitive advantage. It could ship to North America at a cheap rate. Canada Post and the U.S. Postal Service were delivering packages and not being compensated very well, says Schoorl.

* https://www.cbc.ca/radio/costofliving/shipping-canada-china-...

> China is still considered a “transitional” country by the UPU, which means it enjoys a lower rate for sending mail to a developed nation like the US. As a result, mail services from China to the US cost less than Americans are charged by their own postal service for a comparable domestic delivery. This gives Chinese sellers a competitive edge over American sellers, especially in e-commerce platforms like eBay or Amazon, where shipping cost is a major factor for buyers.

* https://medium.com/@contact_53404/why-is-it-so-cheap-to-ship...

* https://en.wikipedia.org/wiki/Universal_Postal_Union