Key currency and import export suggestion

[l35794]

i suggest following
1.Key currency

One city can issue cash because that city money is key currency(example:dollar)

2.import and export

If i build factory1 at A city and build retail store1 at B city.
And if the retail store1 retail factory1's stuff.
Make this mean A city export to B city.

And if one city(A) export to another city(B).
Grow A city's gdp and wage
Make A city's Cash holdings up

3.key currency and import export
If A city can issue cash ,that make A city can import more than export