I've looked again at the KPMG charts. What comes to mind immediately is the foreign tax credit problem (wealth and social security taxes are not creditable as foreign income taxes). Also, the UK, Canada (except Quebec) and (I believe but don't know for sure) Switzerland do not impose social security tax on a retiree receiving benefits. The USA and Quebec and some other countries do, and these additional contributions should increase ultimate benefits.

Questions of cost of living, quality of life, transferability of pensions (and the effectiveness of any totalization agreement) remain. But the chart is a neat lecture aid nonetheless.

As always, US persons will be impacted differently from others. UK domiciliaries (and Canadians who are deemed tax resident in Canada though living abroad) and all those with laws like Canada (Denmark? France? imposing a tax on deemed sale at expatriation) will have to factor in estate planning and capital gain issues.