Many methods have been tried for elimination of black money; we had several rounds of demonetisation, several voluntary disclosure schemes, some schemes to regularise undisclosed foreign assets, and so on. The only commonality between all such measures was their failure to prevent generation of black money. Strategically declaring their black money, tax evaders took full advantage of the frequently announced Government schemes. However, not many of the tax evaders discontinued their tax evading ways, so, after a few years, things came back to square one
A unique measure enacted recently in Iowa providing parents public funding to send their children to private schools, including parochial ones, owed much to its neighbor to the north: Minnesota. It comes in the 40th anniversary of a pair of tax tussles that reached rival results before the U.S. Supreme Court.