From BigWhiteGuy.com (”Adventures of a BigWhiteGuy living in Hong Kong”), comes an explanation of Chinese “Hell Notes”:
The Chinese believe that when someone dies, his spirit goes to the afterlife, where it lives on, doing much the same things it did in life. Surviving relatives want to send gifts to make the afterlife as comfortable as possible. Aside from intricate paper objects such as houses, cars, clothing, watches, mobile phones, appliances and even domestic helpers, Hell Bank Notes are most popular. Burning sends them on their way.
[…]
What kills me is the notes come in such a huge variety of denominations — everything from one cent up to billions of dollars. This means one of two things: either everyone in the afterworld is wealthy beyond imagination, or inflation is staggering. Maybe the dead need a single $1 billion bill to buy a loaf of bread — rather like the 1923 German Reichsmark. Ouch!