No, the CBO study looked at the actual dollars coming from people; as Prof. Mankiw notes, while there might be invididual exceptions the overall figures are as stated.
>the United States have a very progressive tax system
Compared to which system? The system of Sweden or of Uruguay? You of course can find dozens of third world countries, with dysfunctional tax system.
I guess, they are similar studies as can be bought (in dozens) in the country, I live in.
No, Prof. Mankiw's claim is that Mr. Buffett did not include all taxes in that statement.
> > the United States have a very progressive tax system
> Compared to which system?
In absolute terms, according to the CBO's figures. The CBO is the Congressional Budget Office, and is widely reputed to be honest.
Once, the US prided itself to be the most developed nation, today it must compare itself with Uganda and other countries.
Compare tax rates of today with those after the 2nd WW -- the era, where the US flourished most. Today, only the banks of the US are flourishing. When you are no banker and earn below 7 figures a year, you should start to think.
The sentence about "honesty" I will not comment!