In Four Futures: Life After Capitalism, Peter Frase uses metaphor from popular culture, for example, Star Trek, to describe what life might look like after capitalism, whether we evolve into each future or have it thrust upon us on two axis: equality v. hierarchy and abundance v. scarcity.
Communism is equality and abundance. He does not specify how this will look exactly, but he uses a citizens dividend as a possible route to get there (the dividend gives labor a higher supply cost for work, which raises wages and increases abundance as everyone can buy what they need or maybe, if people don't work, less of what they want but don't need).
Increased automation is a possibility I see here, which would give us the same amount of stuff for less work. There is also the problem of professional slaves, like doctors and especially nurses, who are needed and cannot be automated away. They will begin to resent an idle nation, as would soldiers or astronauts. There is also the question of whether the dividend was just for adults or will be adjusted for family size. We already have one just for the kids, but it is about twelve sizes too small and some only collect it at year's end rather than when needed at every paycheck.
Rentism is hierarchy and abundance. The key feature of this future is ownership of intellectual property, both for production and consumption (from branding to bioscience). This also includes land rent paid by the many to the few. I support an ownership alternative, where workers own the means of production of their company, including intellectual property. You could use social insurance collections to buy employee companies, with the contribution equalized so each employee gets the same amount of stock per period.
Going back to the abundance problem, I would develop in-home agriculture (hydroponics and growing meat from stem cells). These homes would be expensive, so the cooperative would give you no interest loans to buy them and may even build them for you. These cooperatives would buy the land and hold it for their members, solving the problem of land rent. I would also keep the benefits of creating intellectual property closer to the actual developers rather than giving them to the capitalists and their pet CEOs. You will get more innovation, not less.
Socialism is where equality meets scarcity. Eco-socialism, which Joel Kovel proposed in his 2000 run for president, falls into this category. Basement agriculture in cooperative built homes could also be a solution here - one that involves government less (although NASA is developing the whole habitat angle, or was, for a mission to Mars). Running out of resources is the theme to this future, although I still think Mathus was wrong. We will always figure out how to grow food, clean water and air and deal with floods (and maybe even control carbon) and will use government, industry and cooperatives to do so. Currently, there is no urgency, however, because enough of the middle class has been bought off with their toys and wages to ignore the urgency of upcoming scarcity. Socialism is never to be seen as a permanent state - it is the road to eventual communism and abundance. If cities can rise out of the Arabian dessert, most anything is possible in dealing with scarcity. The problem is scarcity of distribution, not of actual resources.
Exterminism is where hierarchy meets scarcity. In this future, the elite separate themselves from society and let society begin to dies off or be killed through prison, police violence, war, environmental disaster (see Flint) and cutting welfare benefits. The evidence that this is happening now is hard to dispute. Indeed, Trump seems to champion Muslim exterminism. Zero population growth, rather than dealing with scarcity is a way to keep poor people from breeding - more exterminism. How do we fight this? Blow the whistle and increase that Child Tax Credit that I mentioned above. In cooperatives, every member is in an enclave and every person could be valuable. There are many under-educated geniuses out there who have been given poor educations because of their darker skin. Just look at the drug trade. These are complex enterprises. Recruiting everyone ends scarcity.
My impression in reading this book is not that these are four discrete futures, but four trends that are going on simultaneously. The conclusion of the book states exactly that. Now that we know, we can start doing something about it.