Kin Mueang (กินเมือง), literally "eat the town" was the traditional way of payment for the local administration until the thesaphiban reforms of King Chulalongkorn at the begin of the 20th century.
A more fitting way to translate that term would be "eat from the town", since at those times the administrator like the provincial governors were not paid by the central government, but earned their living directly from the town under them. They had to send a fixed amount to the central government, so any additional funds they could earn from their town was their salary. Thus the more ruthless administrators were the ones who could become the richest, and since the normal populace was not allowed to choose their residence freely they were totally at their governor's mercy.
For the lower administrative posts, the correct term was Kin Tamhaeng (กินตำแหน่ง, eat the position), but the actual system was the same - the official had to deliver a fixed amount to his superior, and any additional funds he could make by his position were his salary. Especially the tax farmers, mostly of Chinese origin, became quite rich in this way.
Though this system was abolished more than 100 years ago, and the government staff became a fixed salary instead, it doesn't mean that after that there were no attempts ways of extract additional salary from the local sources. Of course these were then illegal ways like corruption, but as the salary especially for the lower ranks are hardly appropriate one could think these illegal means were somehow sanctioned by the government.
I am not sure if it's related, but nowadays many of the officials are shuffled around in their posts, it is rare to have a province governor or district head officer to serve in the same locality for more than two years, especially province governors often get moved to a new province after just one year. One reason to do so may be to avoid that these officers built a local income net, in their short time in one specific place they hardly have the time to learn who could bribe them best.