"Socialism is an economy where production is owned and run by the workers for the benefit of the working class"

Isn't that communism?

No. There's a reason why they are two different words. Socialism is after capitalism but before communism in terms of Marxist theory. From my understanding the big difference is there is still competition in socialism and things are privately owned by the workers, where as everything is publicly owned in communism. Remember that during Marx's time it was unusual to have the boss down on the production line working with his employees. Now a days people have become what Seth Godin like to call linchpins. It's not rare to have your boss coding or designing with you if you work at a start-up.

>Simply having a welfare state or some nationalized industries is not socialism.

Yes it is. It is a matter of degree. When you have an income tax, you have socialized income. If you have a "workers factory", you have socialized the means of production.

Your first paragraph seemed like you had the right insights, yet you contradicted yourself by the second.

No, I didn't. Even co-ops that exist today must sell on the capitalist market.

There is no use-value based economic planning today.

Could they not exchange goods with other co-ops?

Well, yes. But that could only provide for a tiny amount of goods - at least if theco-op doesn't want to live in a primitivist hell.

There could be coops around the world that trade with each other to get everything they need?

Yes, if we agree on a primitivist definition of "everything they need", which most likely includes food, shelter entertainment and some artwork - perhaps even basic medicine. But no electric energy, electronics, cars, farm machinery, refrigerators, antibiotics and so on. Building this stuff requires massive amounts of capital.

>Their ideas are as worthless.

Just like Socialism which ruined India.

Socialism and capitalism can be occurring at the same time in the same city. If one company was worker controlled and one company was hierarchically controlled then it would be fine. As long as nobody is forcing somebody into a different system both could work together.

Socialism is more than the worker's ownership of the means of production.

http://www.marxists.org/archive/fromm/works/1961/man/ch06.ht...

Depends on whose definition of socialism you are using.