Abnormally high top rates of tax do not raise more revenue, but they do disincentivise people from investing in businesses.

 

While I could agree with you depending on how you define "abnormal" (i.e, the current surcharges in France, for example, seem rather ludicrous to me) and I know that this is the position taken by the wealthy as a whole, how do you explain what happened in the US in the 90's when we had much higher tax rates than today and much higher levels of both employment and capital investment? And, lordy, lordy, those conditions led to the first time we in the US had a balanced federal deficit! 

 

Warren Buffet asserts that uncertainty, not tax rates, is what drives people to invest or not invest.  I agree with him.  

The 75% rate in France will really act as a disincentive for business.

As for higher rates of tax in the US, well I'm not an expert on that, but I thought even the 1990s top rate was about 40% ?

There's a big difference to motivation between keeping 60% of your money and just getting 25%.

 

Generally, when the Conservatives cut the top rates of tax in the UK, they actually collect more taxes.

 

Finally, it's usually prudent to tax things you want to discourage and subsidize things you want to happen.

 

In Europe, it is often done the opposite way, as we discourage enterprise with high taxes and subsidise lifetime idleness through very gernerous social security payments. 

Such policies guarantee high unemployment.

The 75% rate in France will really act as a disincentive for business.

As for higher rates of tax in the US, well I'm not an expert on that, but I thought even the 1990s top rate was about 40% ?

 

We're going afield (sorry, OP) but, while we US citizens pay a myriad of state and local taxes, one thing we're not doing is paying enough federal tax.  Supposedly 48-52% pay no federal tax at all!  And people like Romney paying 13% of 27 million in income speaks for itself.  Buffett, one of the richest Americans, has paid 17% the last couple of years.  With all the loopholes (bought and paid for by lobbyists, of course), almost nobody pays the top tax rate of 39% (and, besides, that's only assessed on income over a certain level after some income is exempted and generous deductions are applied).  

Talk of 40% rates must seem a piece of cake to those who lived through the 1950s in the UK when the top rate of tax was 97%. And then in the second half of the 1960s, anyone wishing to travel overseas was limited to a maximum of £50 - and this had to include the cost of the transport!