Is this compatible with human nature?
A participatory economy is based on the assumption that people are homo economicus, i.e. that they act out of self-interest. It most certainly does not assume that individuals are “revolutionary saints” who act to promote the social interest (i.e. social efficiency and equity), and then tautologically proclaim that the social interest would, indeed, be served!
In brief, the principle mechanism that compels worker councils pursuing their own self-interest to behave in a socially responsible way is that these councils must demonstrate to other worker and consumer councils that their proposals generate an acceptable excess of social benefits over social costs. For their part, consumer councils must demonstrate that the social cost of the goods they request is consistent with the average work effort ratings of their members. The principle mechanism that compels individually responsible behaviour are effort ratings by one’s work mates and consumption allocations based on effort ratings. The logic is to organise the economy in a way that ensures that the behaviour of homo economicus will be indistinguishable from the behaviour of homo socialis, or put differently, to reward socially responsible behaviour and discourage socially irresponsible behaviour.
While the model assumes that people are homo economicus and is based on institutions that lead people to behave in socially responsible ways out of self-interest, it is not so farfetched to hope that many years of practicing social responsibility, and observing that others have practiced social responsibility as well, will move people closer to homo socialis in their economic relations. There is plenty of evidence that people do behave as homo socialis today — toward family members, friends, and various communities where members feel solidarity for one another. So this is not behaviour foreign to the human species when we have good reason to trust rather mistrust each other.