How have Germany, the Netherlands, Finland and Austria managed to reduce their public debt ratios?

There is a considerable difference between the public debt ratio trajectories of Germany, the Netherlands, Finland and Austria and the other euro-zone countries (if we look outside the euro zone, the same observation can be made for Denmark and Sweden). How have these countries (which have begun to be called “frugal”) managed to maintain a low public debt ratio? Less generous social policies (healthcare, education, pensions, families, housing)? A stronger performance by the state in the delivery of healthcare and education? A higher tax burden or higher public sector productivity ? A higher employment rate, leading to less need for public transfer payments and a broader tax base? An economy that is less often underemployed? Lower interest rates and/or higher potential growth? The key explanations seem to be: Lower pension spending; Higher productivity in the public sector; A higher employment rate and lower unemployment rate; Lower interest rates and higher potential growth. Public finances are better managed in the “frugal” countries at the same time as the ir macroeconomic situation is more favourable.