.. purchases of financial assets. Much of what is counted for as "investment" in that shell game is buying and selling used financial assets.

There is no less reason for those who have experience capital gains to a substantial extent due to the overall growth of the economic system to pay a tax out of the income flow they are appropriating than there is for those who receive labor or rentier income.

Indeed, there is arguably more reason, because the total amount capital gains is more dependent on economic growth than the total amount of income earned.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.