The income must be cash or cash-equivalent (as opposed to a monopsony, where a single payer buys tries to negotiate lower rates with, say, farms and landlords)

The income must be cash or cash-equivalent (as opposed to a monopsony, where a single payer buys tries to negotiate lower rates with, say, farms and landlords) so that purchasing occurs competitively. Government's role would be to break up monopolies on basic goods and services.