This is a lazy idea that keeps getting trotted out. The 90% tax bracket only existed on paper, with an effective rate closer to 40%. Economists have shown that tax revenue remained remarkably unchanged, while having negative consequences for investment and productive use of capital. Instead, the relative prosperity of workers during that time came from a lack of global industrial competition and a massive post-war manufacturing monopoly. Without a completely sealed, loophole-free tax system and total global compliance, implementing a 90% tax rate today would simply result in widespread tax avoidance, capital flight, and a reduction in domestic investment. The rich do not make the bulk of their wealth through a salary (many taking $0 / year) like they did back then, but rather through stock options, etc.