It's possible if the government plays around with the tax system too much while being composed of idiots who don't understand basic math or don't understand why

It's possible if the government plays around with the tax system too much while being composed of idiots who don't understand basic math or don't understand why tax rates over 100% are bad. As an example, former Croatian prime minister Jadranka Kosor introduced a new tax according to which if your after-tax income was above a certain limit, you had to pay an additional 4% of that income as tax. Of course this resulted in >100% marginal tax rates. I assume Sweden had a similar situation, where it wasn't actually a 102% tax rate, but a combination of multiple different taxes that resulted in an effective tax rate over 100%. The people who created those taxes either didn't care or were simply too stupid to notice the problem.