… is from page 37 of Thomas Sowell’s Compassion Versus Guilt, a 1987 collection of some of his popular essays; specifically, it’s from Sowell’s September 7th, 1984, column titled “Work and Output” (original emphasis):
The whole connection between work and the output we live on is being lost in many people’s minds. To many, the country somehow has wealth, which we should all share – and “fairly.” The most basic fairness of contributing to the efforts that produced what you want to share escapes them completely.