Oldie but goodie. A piece of fiction describing how a computer system can do the job of human managers at fast food restaurants (scarily plausible), how this leads to a dystopia (slowly getting implausible), and how to avoid this scenario and reach utopia (give me a break).
"Post-scarcity economy" is an impossible concept even in principle (assuming a human society, at any rate). Beyond a certain minimal standard of living, which is in fact quite low by today's standards, most of the things people really care about are zero-sum. They will struggle just as mightily and eagerly to wrest those for themselves no matter how cheap, plentiful, and high-quality non-zero-sum stuff gets. Moreover, habitable land is always zero-sum, which further complicates things.
For those with less ambition and/or ability, this has a twofold effect. On the one side, it benefits them because in a decently functioning polity, people's efforts to get ahead in life in the hope of zero-sum gains will result in a growing economy making non-zero-sum stuff increasingly cheap, plentiful, and high-quality. On the other hand, it is bad because some things are zero-sum but nevertheless essential for life, most notably habitable land, and people's struggle to get ahead in zero-sum efforts drives the price of these way up. This makes it necessary to work almost as hard as the most ambitious and prosperous folk to be able to afford the increasing price of lodging and other essential access to zero-sum things.
Thus in the contemporary developed world we have a situation where nobody is in danger of starving or not having warm enough clothes, but homelessness is a very realistic threat for poorer people. (As an even more striking illustration of the same phenomenon, in recent years even cell phones and computers have become affordable to many of the homeless folk.) The Manna story also illustrates the same principle accurately: the state finds feeding and clothing the unemployable masses adequately a trivial expense, but the land to house them is expensive and scarce so they have to live packed together like sardines.
How about a totalitarian government with high technology and fertility management?