How did the culture of giving money to teachers originate in Northeast China? It is said that every student's parent has to give, but does every teacher receive it, or only the homeroom teacher?

Besides the three northeastern provinces, are there any other provinces with similar practices?
It's unheard of in the South. Are Southern teachers not willing to work if they accept money like this? Do they want to be labeled as pandas?
Maybe Northeasterners are too wealthy, and they give some to teachers to improve their lives?