I worked for a COOP grocery store in Arizona for two years best job ever. The Mars series by Kim Stanley Robinson has some great structures for COOPs. One of my favorite structures was an internship. You worked for a few years to earn a stake in the company. After a few years you owned that part and you could use it to buy into the next company you work at, then eventually retire with it. This is in a society built on a science outpost economy, where not even air is easily accessible, so most basic things tend to be already provided for. If you are interested there, I have an epub I got for free somewhere, there are also places called libraries. Robinson is always heavy on the sci in his fiction, any science he has a great viewpoint on it. I even really like his spiritual views, a living master.