The Wealth of Nations by Part 1 Chapter 10 Page 98

has always been rather to lower them than to raise them. But the law has upon many occasions attempted to raise the wages of curates, and for the dignity of the church, to oblige the rectors of parishes to give them more than the wretched maintenance which they themselves might be willing to accept of. And in both cases the law seems to have been equally ineffectual, and has never either been able to raise the wages of curates, or to sink those of labourers to the degree that was intended; because it has never been able to hinder either the one from being willing to accept of less than the legal allowance, on account of the indigence of their situation and the multitude of their competitors; or the other from receiving more, on account of the contrary competition of those who expected to derive either profit or pleasure from employing them.