If you do it right, not much(just look at Countries like Denmark, Sweden, or Finland), the key is to first put the protections in place(to make sure extreme-poverty can't happen), and then start adjusting Free-Market into a Planned-Market.
And since we're already in a Planned-Market(since the FED, and Central-Banks are actually floating the Financial Markets the last 5 years) that changed isn't even that big.
The only thing that would change is the loss of fear, for the work-force, which in turn would improve economics, so more socialist-culture would actually improve consumption(a nice paradox).
Could be a starter ^^


