Neat solution to a tax problem in China

When I was in Shanghai, I talked to my friend's GF a bit about a tax problem that the Chinese government was having and how they addressed it.

The issue was that a lot of small businesses weren't reporting their taxable income accurately. Since most transactions are carried out with cash, it is easy to avoid producing a paper trail, especially at places like small restaurants, which are everywhere. For example, I've rarely been given a formal receipt in any of the places that I've eaten while here. This was taking tax revenue away from the government.

In order to stop this, the government added a scratch-off-lottery component to receipts, with cash prizes of 50, 100, 500 yuan, etc, a few years ago. They effectively turned receipts into scratch-off lottery tickets. In order to play and win, people had to ask for their receipts at stores, generating a taxable paper trail in the process.

From what she told me, the the whole thing was pretty effective, and everywhere we went, she asked for the receipt to try her luck.