Why are they collecting trillions in foreign securities?
So the countries they buy the securities from have enough money to buy the products China produces.
It's like a giant department store credit card. They issue you the card hoping you'll run up debt buying their products, but even if you don't buy anything form them, they still make money off your interest payments.
Makes sense, thanks. I still don't really understand the effects of devaluing currency on industry though.
Using currency devaluation, the Chinese government is actually giving subsidies to exporting-oriented industry, while damaging ordinary citizens by introducing inflation. The exporting-based economy have been a long-term policy of China since the economic reform. The government acts in this way for these two reasons:
1. The demands inside China is not enough to create many jobs. And the Chinese government deeply fears the unemployment rates, probably much more than any western countries, because the dissatisfaction to the government is about to burst at any time.
2. Exporting-based economy is the best way to use the price signal (of which the origins is from abroad, not China) to guide the resource allocation without the adoption of a fully functional free market. A truly free market economic system is the last thing the Chinese government wants to see, because it will weaken and finally destroy any form of tyranny and dictatorship.