In his State of the Union address, President Barack Obama talked about Americans paying their fair share in taxes. For most of my life, I thought that I had a reasonably good idea about what "fair" means — except for that period when my children were young and "fair" meant getting precisely what they wanted, when they wanted it, and if they didn't get it instantly it was "not fair." The meaning of the word became especially tricky when each of my children wanted something different. How could something be fair to one and "not fair" to the others? Shouldn't fairness be something that takes into consideration the needs and desires of all of them, as well as my wife and me?

"Fair" is one of those vague words that means different things to different people and sometimes different things to someone at different times in his or her life. I fondly remember that, when we were children, my mother insisted on spending an equal amount on Christmas gifts for my siblings and me, which sometimes resulted in an extra stick of chewing gum in someone's stocking to even things out. I thought that was fair. As she grew older, my mother's determination of fairness evolved to take into consideration the relative wealth of my sisters and me, and I think that is fair too.

We should begin a national dialogue to ascertain what "fair" means. Perhaps the way in which voters define that word will determine the result of our upcoming presidential election. To kick things off, I am proposing several questions about tax fairness.

Starting with what I hope is an easy one: Would it be fair to have people living in poverty pay no federal income tax? I think that would be fair. I also think that it would be fair for those people to pay no Social Security or Medicare taxes (which, for someone earning $30,000 per year, come to almost $2,300).

Is it fair that almost half of Americans pay no federal income tax? That doesn't strike me as fair, nor does it seem fair to me that Senate and House staffers have unpaid 2010 federal income taxes of more than $10 million, or that federal employees as a group still owe more than $1 billion in 2010 federal income taxes.

Is it fair that a professional athlete earning $3 million per year should pay more in federal income taxes than a mail carrier earning $60,000 per year? Sure — but should that athlete pay 50 times more in federal income taxes than that mail carrier? Should he pay more than 50 times what that mail carrier pays?

Much has been written about the respective tax rates of Warren Buffett and his secretary, but almost completely overlooked is the disparate tax treatment of similarly situated middle-class taxpayers. Is it fair that two people, each of whom earns an identical amount, can have very different tax liabilities merely because one rents and the other owns a home with a mortgage and pays property taxes? That doesn't seem fair to me.

Finally, should the top 1 percent of taxpayers pay more than one-third of the nation's taxes? Should the top 5 percent of taxpayers pay 60 percent of the nation's taxes? They do, and whether they should ought to depend on whether they garner more than one-third or 60 percent of the nation's income — not on whether "they can afford it."

Try posing some tax fairness questions yourself, but please don't think of fairness the way an 8-year-old would.

Bob Price, now retired, served as general counsel at both Legg Mason and Alex. Brown & Sons. His email is