People are willing to pay money for the privilege of lending money to the German government. Yet the German government, including the supposedly left-wing SPD, is still holding to the schwarze Null ("black zero," meaning a balanced budget). A rational policy in this environment would be to take advantage of negative interest rates to finance stimulus. Instead, they're dogmatically holding to the zero-deficit policy.
As for the SPD being left-wing: traditional political categories quickly break down when applied to Germany, the continuum is "far left, nothing, nothing, the super majority in the center, nothing, nothing, far right". There's very little actual difference between the "conservative" CDU, "social democrat" SPD, the socially progressive Green party and the "free markets will take care of that, whatever it is" FDP when it comes down to policies, which is also why Germany's policies don't change a lot when the government changes (the conservatives removed the military draft, the social democrats cut back the social system, and the pacifist Greens & social democrats went to war in Kosovo).
> A rational policy in this environment would be to take advantage of negative interest rates to finance stimulus.
In a time of growth, record tax income, strong-ish inflation (thank god for cellphones and smart tvs or it would shoot up like crazy)?
Taxes on income, yes. Taxes on spending, yes. Taxes on capital gains, not really. And taxes on property are virtually nonexistent. And where's that financial transaction tax people were talking about 10 years ago?
The share of tax revenue they provide isn't that large, it's about as much as car tax. Even if they doubled it, it wouldn't really matter. Property taxes do exist, but they aren't a federal issue, they (together with a tax on company earnings) fund the local communities, the federal level is funded by income tax and sales tax, mostly.
> And where's that financial transaction tax people were talking about 10 years ago?
It was mostly activists talking about it in a "if we all got together and did this world wide, it would be so nice" kind of way. I don't see that happening any time soon.
Germany is on the verge of recession. Growth was negative last quarter. Inflation is around 1%, which is rather low.
Unless the state is expecting bond rates to remain negative indefinitely.