Social democracy combines the inclusive economic institution of socialism with the inclusive political institution of democracy. In short people have a say in both their economy and government. Listing things off the top of my head that a social democracy should include are things like health care paid for by the government, a government run retirement program like social security, food stamps provided by the government, government housing, government maintained public drinking fountains, government provided internet access. If something is needed routinely by people in order to survive then the government should have a hand in making sure that they get that thing. Market economies by default fire the poorest customer in pursuit of profit. It isn't profitable to house everyone, so not everyone gets a roof over their head, but everyone needs shelter in order to live.

In the spirit of inclusive economic and political institution alone, I would say workers owning the companies they work for is consistent with social democracy. Corporations will still be pursing the profit motive. The difference is that the C-staff will beholden to make profit for the workers and not the share holders. The system is still reliant on a welfare state to avoid people falling through the cracks and make sure everyone gets their basic necessities. I'm sure some social democrats would say we don't have to go this far and that a mixed economy is sufficient. I have come to the opinion that we do need to go farther in this specific regard. As long as the owner class exists, even with sufficient wealth distribution, which is still needed, they will be incentivized to overthrow democracy. By having one class of people, workers, there is no class with the incentive to overturn democracy for profit. We need to have a real say in our place of work, as it has a tremendous impact on our lives and the best way to do that is for workers to own it.