The basic perception is that the FDP and the Greens have similar voters (young, urban, well-educated) and much in common in social policy, but are a long way apart on economic policy.

That at least was the conclusion of a Berlin Social Science Center's (WZB) analysis of the parties' manifestoes: The Greens and the FDP both have broadly progressive ideas about socio-cultural issues like gender and racial equality and human rights, but lean different ways on economic solutions to social problems. 

And, well, that's about it.

More than that, they could hardly be further apart on what surveys said was the biggest issue in this election campaign: The climate crisis. 

The FDP has the least ambitious climate target of all the major German parties -- committing only to get the country carbon neutral by 2050, via emission trading schemes, while the Green party wants Germany to be carbon neutral by 2041, and wants to shut down Germany's remaining coal power stations by 2030, eight years ahead of the country's current target.