SK in CV wrote:But I could

[an]

[quote=SK in CV]But I could make a pretty strong argument that increasing the top tax rate, particuarly on businesses, would be good for the economy, but not to 90%. Somewhere between 50 and 60% would help. Higher top tax rates encourage businesses to spend money when the government pays for half of it.[/quote]
Alright, lets take a look at what the tax brackets were the last time we saw >60% top rate.

Rate 1981 dollar 2010 dollar
0% <2300
14% 2300 5,444.71
16% 3400 8048.71 
18% 4400 10415.97 
19% 6500 15,387.23
21% 8500 20121.77 
24% 10800 25,566.48
26% 12900 30537.74 
30% 15000 35509.00 
34% 18200 43084.25 
39% 23500 55630.77 
44% 28800 68177.28 
49% 34100 80723.79 
55% 41500 98241.57 
63% 55300 130909.85 
68% 81800 193642.42 
70% 108300 256374.99 

Lets look at what the rates look like in 1963 when top rate was 91%:

Rate 1963 dollar 2011 dollar
20% $0.00 $0.00
22% $2,000.00 $14,086.18
26% $4,000.00 $28,172.36
30% $6,000.00 $42,258.55
34% $8,000.00 $56,344.73
38% $10,000.00 $70,430.91
43% $12,000.00 $84,517.09
47% $14,000.00 $98,603.27
50% $16,000.00 $112,689.45
53% $18,000.00 $126,775.64
56% $20,000.00 $140,861.82
59% $22,000.00 $154,948.00
62% $26,000.00 $183,120.36
65% $32,000.00 $225,378.91
69% $38,000.00 $267,637.45
72% $44,000.00 $309,896.00
75% $50,000.00 $352,154.55
78% $60,000.00 $422,585.45
81% $70,000.00 $493,016.36
84% $80,000.00 $563,447.27
87% $90,000.00 $633,878.18
89% $100,000.00 $704,309.09
90% $150,000.00 $1,056,463.64
91% $200,000.00 $1,408,618.18

As you can see, people making $250k in today's dollar didn't pay 91% back then as well.

What's also interesting in 1963, when you say was good period of growth, the lowest tax rate was 20% from the very first dollar you make. It also ramp up very fast where by the time you get to $112k, the tax rate was 50%.