That's one way to look at it. Another way is to say that if wealth tax offsets growth exactly, then the government has taken the difference of what your wealth would have been after 60 years. For example,
1 - 1000*(1-.01+.01)^60 / [1000*(1+.01)^60] ~= 45% taken from the government
Which is the same as the author of the article found.
Except the article implies that you might be nearly destitute. The article seems to imply that you'd have very little wealth left, even though that's not the case.
I just read the article again, and I don't see any language in it to support the idea that it's implying you'd have any less wealth than it calculates that you would.
I'm not saying his math is not correct, I'm saying it is misleading that he does not even mention growth at all. He presents carefully selected numbers, ignores tons of stuff around (growth, but also the fact that wealth would be marginal tax) and then makes a bold claim that people will believe in.
