It was the kokushi's right to impose the zoyo, and among the kokushi there was some who imposed the zoyo for personal use; it is commonly accepted that the zoyo became a burden to the komin (the registered people, especially farmers, under the Ritsuryo system) and thus caused the handen farmers (farmers whom the government had given the handen, or the allotted land for farming) to decline, abandon the land and flee to other domains.
雑徭の賦課は国司の権限であり、なかには私用で雑徭を課す国司もおり、公民の負担となり班田農民の没落・逃散を促したとする見解が通説である。