What the author calls a "beautiful" system to me seems to be bordering on fraud and undermining what the law was originally intended to do. Basically random small towns hire consulting companies who run advertising campaigns asking people nationwide to send them their 40% "hometown donation" and get 20% of it back as a "gift", thus conveniently evading half their taxes? Who exactly is benefiting here?
It's cultural. Japan has a cultural of reciprocal gift giving that underpins this entire exchange.
Basically it's a decentralizing force
It prevents a doom loop where everyone moves to Tokyo because that's where all the resources are because everyone moves to Tokyo as the rest of the country hollows out
It sounds less like fraud and more like gamification of incentives. Fraud requires someone to be defrauded. The rules of a game are laid bare, thus looks to me to be an emergent cultural quirk that benefits everybody.
