Legal in example sentence
For most of the twentieth century, large chunks of the world remained desperately poor for one or more of four related reasons: (1) criminal misgovernment; (2) lack of the machines to do anything useful and productive in the world economy besides subsistence agriculture and unskilled service work; (3) lack of the public education system needed to give people the literacy and the skills to operate the machines; and (4) barriers (legal and physical) that kept people where demand was low from selling the products of their work where demand was high.