Not too long ago I looked up the tax rates of various countries, including Sweden. If I remember correctly Sweden had a personal income tax rate starting at 30% (USA's bottom is 0%) for lower earner and going up to 68% (USA's is around 38%) for higher earners. Can't remember what their corporate rate was but there are other taxes like local taxes, VAT (sales tax), etc... that were pretty high. I think VAT was around 25%. Some other countries I looked at that had universal health care had lower tax rates because they had less social services overall than Sweden. Some countries also had a separate healthcare tax besides personal income tax that was at a set rate - kind of like our Medicare and Social Security tax is. I'll try to find the link as it was pretty interesting.
As for how much I think we should all pay towards universal healthcare? Hmmm.... not sure. I kind of like the idea of expanding Medicare to allow all people to buy insurance at a more affordable contracted fixed rate. I also like the idea of a separate flat tax rate based on gross income that everyone pays (again like we do for Medicare and SS) and not just the wealthy. Also a matching % flat rate corporate tax that businesses pays/employee instead of providing health insurance for them (although they still can provide private health insurance to their employees as a benefit if they want). Lower income/asset people could have government aid to pay for health insurance. Probably wouldn't be enough moolah from those taxes to pay for it all though so may have to have some personal income tax increases as well. 10% on top of what we already pay? Too much? Not enough?
From: http://www.taxrates.cc/html/sweden-tax-rates.html
Individuals pay both national income tax and municipal income tax. In 2010, individual income tax rates in Sweden change between 54% and 61%, 57.77% being the average tax rate, Corporate tax rate is 26.3% and VAT is 25%, Dividend and interest income are taxed at a flat rate of 30%. Capital income is taxed separately from income from employment at a rate of 30%. Social security contributions – Contributions by the self employed amount to 29.71% (for 2010), plus a pension insurance fee of 7%, Social security contributions – The general aggregate contribution by an employer on behalf of an employee is 31.42% (for 2010).