From pg 12-13 of Colin Crouch’s The Strange Non-Death of Neoliberalism:
These then were the principal ingredients of the socioeconomic order that came eventually to be called social democratic, without initial capital letters:
1 – Keynesian demand management in which government action, far from trying to destroy markets, sought to sustain them at levels avoiding self-destructive booms and slumps alike;
2 – strong welfare states that enabled people to receive some services in kind rather than through the market and some forms of income not dependent on market performance or property-ownership, bringing diversity to what would otherwise be purely market-determined life chances;
3 – in some cases, neo-corporatist industrial relations, trying to balance workers’ freedom to organize with the need for labour markets to function efficiently.
With the third being crucial because otherwise inflation leads individual unions to seek higher wages to protect their members, in the process exasperating the macro-economic problem they are seeking a solution to.