By their tiny banknotes you shall know them

Odd little Shanghai/Beijing difference:

In Shanghai, the smallest currency bill I routinely saw was the 5 kuai (RMB) note. It's the violet-colored, Mao-adorned one at left in the picture below. (Click on the photo to see it enlarged.) It's worth about 67 cents US. Anything smaller was a coin.
http://i142.photobucket.com/albums/r96/jfallows/IMG_4190.jpg

In Beijing I very rarely get coins and instead wind up with pockets full of amazingly penny-ante notes. The 1 kuai note (13.5 cents) is omnipresent. It's the greenish one with Mao on the right, above. What I still can't quite believe are the 1/2, 1/5th, and 1/10th kuai notes, the latter worth just over one cent, that I virtually never saw in Shanghai and frequently get in change at stores in Beijing, as I have in rural China. The 1 jiao note, one tenth of an RMB, is the brownish one at top, featuring ethnic peoples rather than Mao. Indeed this afternoon my wife and I used the very bills in this picture to pay all-paper-money exact change for purchases of 2.3 kuai (31 cents) and 3.5 kuai (47 cents) at a the local outdoor produce market. And we came home with a lot of onions, apples, and potatoes...

No master theory here, but the difference is striking. It may help explain why Shanghai thinks it is more moderne -- and why there are so many more coin-operated vending machines there. And I suppose the use of 1 jiao notes is no odder than the continued existence of the U.S. penny, which costs more to produce than it is worth.