In the leaked video published by Mother Jones, Mitt Romney claimed that 47% of Americans "pay no income tax", people who he could "never convince … to take personal responsibility and care for their lives".

He described such people as those "who are dependent upon government, who believe that they are victims, who believe the government has a responsibility to care for them, who believe that they are entitled to healthcare, to food, to housing, to you-name-it".

At a press conference designed to limit the damage to his election campaign, he did not disavow the claim but said Obama's policies are "attractive to people who do not pay taxes".

Romney's headline assertion that 47% of Americans pay no income tax is almost correct, assuming he was referring to federal income tax. The Tax Policy Centre said that in 2011 46.4% of people paid no federal income tax. But his suggestion that such people do not "take personal responsibility and care for their lives" warrants further investigation.

Firstly, some of those people who did not pay income tax still paid payroll taxes, for social security and Medicare, so that it was only 18.1% of households that did not pay any income or payroll taxes. Given that there are sales taxes, state property taxes and state income taxes these people are still paying some tax – at what point you are deemed to be taking personal responsibility is subjective.

Of the 18.1% paying no income or payroll taxes, more than half (10.3% of all households) were elderly, so retired people who may well have paid income and payroll taxes, as well as others, during their working lives. Of the remainder, 6.9% of all households did not pay income or payroll taxes, essentially because they were poor, leaving 1% of "others" who did not pay either of these two types of taxes. Presumably, within the "others" category would fall the likes of six of the 400 US tax filers in 2009 with the highest adjusted gross income (at least $77m), who, according to Internal Revenue Service studies, paid no US income tax, and the 19,551 US households with income above $200,000 who owed no US or foreign income tax.

The percentage of people paying no federal income tax was even higher in 2008 and 2009 (50.8% in each of those years) but it is no coincidence that such figures have gone up during a recession (the figure was 39.9% in 2007).

Howard Gleckman wrote for Tax Policy Centre about the situation in 2009: "You may have noticed that we've had a recession lately. And here is a powerful insight: When people's incomes decline so too does their income tax (at least most of the time) ... there is, however, another reason why some people don't pay. For decades, both Democratic and Republican governments have made conscious policy decisions to remove low-income working families from the income tax rolls. And, guess what, sometimes government policy works exactly as intended. That's what happened this time."

Michael Cooper for the New York Times writes: "A major reason that many poor people no longer pay federal income taxes is the Earned Income Tax Credit, which has long been supported by Republicans. The credit was added to the tax code when Gerald Ford was president, and was expanded by President Reagan in 1986 and by George Bush Sr."

So would Romney like to see higher taxes? Or perhaps just for the poor?