There's an interesting article here

http://www.taxfoundation.org/blog/show/27134.html
https://web.archive.org/web/20110930062345/http://www.taxfoundation.org/blog/show/27134.html

It compares Percentage share of income tax paid by the richest decile with their share of market income.

1. Share of taxes of richest decile
     2. Share of market income of richest decile
         3. Ratio of shares for richest decile (1/2)

Australia
36.8 28.6 1.29

Austria
28.5 26.1 1.10

Belgium
25.4 27.1 0.94

Canada
35.8 29.3 1.22

Czech Republic
34.3 29.4 1.17

Denmark
26.2 25.7 1.02

Finland
32.3 26.9 1.20

France
28.0 25.5 1.10

Germany
31.2 29.2 1.07

Iceland
21.6 24.0 0.90

Ireland
39.1 30.9 1.26

Italy
42.2 35.8 1.18

Japan
28.5 28.1 1.01

Korea
27.4 23.4 1.17

Luxembourg
30.3 26.4 1.15

Netherlands
35.2 27.5 1.28

New Zealand
35.9 30.3 1.19

Norway
27.4 28.9 0.95

Poland
28.3 33.9 0.84

Slovak Republic
32.0 28.0 1.14

Sweden
26.7 26.6 1.00

Switzerland
20.9 23.5 0.89

United Kingdom
38.6 32.3 1.20

United States
45.1 33.5 1.35

OECD-24
31.6 28.4 1.11

Market income includes a lot of non salary stuff. Details here

http://www.keepeek.com/Digital-Asset-Management/oecd/social-issues-migration-health/growing-unequal_9789264044197-en

page 92.

So it's interesting that on a plausible model of fairness US>UK>Sweden

Now it's interesting to look at the effect of top tax rate on the share of total income tax paid by the richest 10%

Top tax rates are here

http://www.nationmaster.com/red/graph/tax_hig_mar_tax_rat_ind_rat-highest-marginal-tax-rate-individual&b_printable=1

You end up with this

"Country","1. Share of taxes of richest decile","Top tax rate"
"Australia",36.8,45
"Austria",28.5,50
"Belgium",25.4,50
"Canada",35.8,29
"Czech Republic",34.3,15
"Denmark",26.2,15
"Finland",32.3,30.5
"France",28.0,40
"Germany",31.2,45
"Greece1",36.8,
"Hungary1",36.8,
"Iceland",21.6,37.2
"Ireland",39.1,46
"Italy",42.2,43
"Japan",28.5,50
"Korea",27.4,
"Luxembourg",30.3,38.9
"Mexico1",36.8,
"Netherlands",35.2,52
"New Zealand",35.9,38
"Norway",27.4,40
"Poland",28.3,32
"Portugal1,2",36.8,
"Slovak Republic",32.0,19
"Spain1,2",36.8,
"Sweden",26.7,56.74
"Switzerland",20.9,40
"Turkey1",36.8,
"United Kingdom",38.6,40
"United States",45.1,35

Plot that and you see this

http://imgur.com/n5RWr

So it's a bit of a mess. One thing you can say is that high top tax rates are no panacea. It seems like around 40% is about right.

Countries that have higher tax rates have a lower maximum share of total income tax paid by the top 10%. Presumably this is caused by people cashing out when their taxes go up.

Actually the best share of income tax by the richest 10% is in the US where top tax rate is 35%. The UK does a bit worse when it had a 40% tax - the 50% tax was not introduced when this study was done. No country with a top tax rate of 50% or more is able to collect more tax than the UK.

If you flip the  axes, add country labels and a trend line you get this

http://imgur.com/zaeEh

You can clearly see that increasing top tax rate does not increase the percentage of total tax paid by the top 10%. I.e. the UK should have cut its top tax rate to 35% rather than increasing it to 50%. That would lead to a higher percentage of total tax paid by the top 10%. It would also lead to more "fairness", i.e. the top 10% share of taxes / their share of national market income would increase.

Here's one for just the Nordic countries. The argument is that they are very comparable because they are so similar. Firstly culturally, particularly the Scandinavian ones. Secondly the share of market income by the richest decile is quite similar.

http://i.imgur.com/q5WNJ.gif

So even with a bunch of countries which are very similar with populations which are relatively sympathetic to high marginal tax rates and egalitarian ideas it turns out that as you increase the top marginal tax rate the amount of tax you collect from the richest decile drops.

What is probably happening is that people like the idea of increased egalitarianism when they chat about it at dinner parties after a few glasses of wine and might even vote for it. When the government actually increases taxes to make it happen they decide to move money offshore or into a company and so total tax revenues actually fall. Conversely cutting top tax rates makes complicated tax minimization strategies harder to justify, do people stop using them and start paying tax.

Laffer was right, even amongst the Scandinavians.