People can usually buy same day as travel in the US, too. Some flights might be sold out, some fares may be higher... but others will still be quite low. It's just uncommon, if you know you'll be flying, because of the risks.
Are you suggesting there's no risk of finding either a higher price or no seats when waiting until the day of travel in China? If so, there may be a yield-management inefficiency where someone else is losing out, and seats are often going empty.
Are you suggesting there's no risk of finding either a higher price or no seats when waiting until the day of travel in China? If so, there may be a yield-management inefficiency where someone else is losing out, and seats are often going empty.