The proposed Swedish legislation about an Angel Investor Tax Deduction got pretty poor feedback from different government organisations and interest groups. After looking a bit closer, but not in-depth, I can understand why.
The rules seem quite complex, probably in order to avoid tax arbitrage, which probably is good for no one. The deduction isn't for the individual investment, but against capital gains taxes. So in order to fully qualify, an angel investor needs capital gains of half the size of the investment. Otherwise, the deduction is 30 % of the maximum deduction. Which is in-line with Swedish capital gains taxation.
Coherent taxation-wise, but not simple nor very predictable.