They do hurt the economy.
The reason they didn't hurt the economy back then was because nobody ever actually paid those astronomically high rates.
YES THEY DID!
A guy making a million in today's dollars would pay $664,000 in taxes in 1963. I'm pretty sure that is more than astronomical on your own scale.
You will not be allowed to get by with that. Provide some sort of data that backs up your claim.
For those math challenged and who can't google.
1) $1,000,000 in 1963 dollars was $135,000
DollarTimes.com | Inflation Calculator
Tax brackets in 1963:
$0 - $4,000 20.00%
$4,000 - $8,000 22.00%
$8,000 - $12,000 26.00%
$12,000 - $16,000 30.00%
$16,000 - $20,000 34.00%
$20,000 - $24,000 38.00%
$24,000 - $28,000 43.00%
$28,000 - $32,000 47.00%
$32,000 - $36,000 50.00%
$36,000 - $40,000 53.00%
$40,000 - $44,000 56.00%
$44,000 - $52,000 59.00%
$52,000 - $64,000 62.00%
$64,000 - $76,000 65.00%
$76,000 - $88,000 69.00%
$88,000 - $100,000 72.00%
$100,000 - $120,000 75.00%
$120,000 - $140,000 78.00%
$140,000 - $160,000 81.00%
$160,000 - $180,000 84.00%
$180,000 - $200,000 87.00%
$200,000 - $300,000 89.00%
$300,000 - $400,000 90.00%
$400,000 - and over 91.0%
http://www.stanford.edu/class/polisci120a/immigration/Federal Tax Brackets.pdf
According to this table, a person making $140,000 would pay $84240 in taxes, or 60% (I was a bit off, but not by much).