This is just one of the stories from our “I’ve Always Wondered” series, where we tackle all of your questions about the world of business, no matter how big or small. Ever wondered if recycling is worth it? Or how store brands stack up against name brands? Check out more from the series here.Ryan S. asks: Living in Berkeley where $100,000 income qualifies for affordable housing, I look at most of the country where $100,000 is a great income. I wonder what would happen if the income tax levels were linked to cost of living. A house in St. Louis, Missouri, is just one-fourth of the cost of a typical San Francisco home, which can set you back more than $1.1 million. Because your salary won’t go as far in an area with a high cost of living, like San Francisco, it makes sense to envision a tax system that would charge you a lower tax rate in more expensive areas and a higher tax rate in cheaper regions. “It's been proposed by academics. This isn't a crazy idea or anything like that,” said Jeffrey Kahn, a law professor at Florida State University. But such a proposal would be too administratively complex and politically unpopular, experts told Marketplace. There are elements of the tax system that already take into account the cost of living, like the home mortgage interest deduction, while some experts say that targeted proposals would be more effective. Implementing a cost-of-living tax proposalFirst of all, defining the “cost of living” might be harder than you think.“Is it based on home value? Do you take the median salary or gas prices? There are ways to do it, but obviously it would add another wrinkle to figuring out your taxes, and we have a complex enough system as it is,” Kahn said. Being in an area with a higher cost of living also comes with a host of benefits that you might not get in an area with a lower cost of living. “People are paying to be in more expensive areas to be in more productive jobs. They pay better,” said David Albouy, an economics professor at the University of Illinois Urbana-Champaign. Cost of living differences are also based on “quality-of-life differences,” which take into account factors like a nice climate, good beaches and high-achieving peers, Albouy said. “What can happen is that we end up giving people a tax break for living in the nicest parts of America, the highest quality-of-life neighborhoods, the California beach towns,” Albouy said. “There's no reason for the government to encourage that.” There are already bidding wars in these areas over land and housing, so if people get tax breaks, they’ll bid even more, driving up prices, Albouy said.Such a proposal is probably also politically unfeasible, given that Republicans currently control all three branches of the government and many areas with a high cost of living are in blue states. “I'm not sure Congress would be willing to say we're going to lessen the tax burden of those who live in New York City and San Francisco and raise the tax burden on those in red states like Iowa,” Kahn said. Current “cost-of-living” deductions The U.S. allows you to deduct the interest on your mortgage, which does address the cost of housing to some degree. “If you are in New York City and buying a $2 million apartment, your loan is going to be bigger, which means you're going to get a larger deduction,” Kahn said. “If you live in the middle of nowhere, Iowa, you didn't spend $2 million. Your loan isn't quite as big.” Business owners also get to deduct their expenses, Kahn pointed out. So if we assume they’re paying more in these areas with a higher cost of living, then they get to write off more of their expenses. Some experts do think our tax system could do a better job of helping those who are struggling financially, but through more targeted proposals. Ariel Jurow Kleiman, a law professor at the University of Southern California, said we could tie the standard deduction to poverty thresholds that are adjusted based on where you live. That would ensure that no one living in poverty pays the income tax, she said. “Everybody, even wealthy taxpayers, benefit from higher standard deductions,” Jurow Kleiman said. The U.S. could also offer renters’ tax credits, she said. Under some of the renters’ credit proposals that have been put forth, renters wouldn’t have to pay more than 30% of their income. They could get tax credits on a dollar-for-dollar basis for any amount they pay above that 30% threshold. “Broadly speaking, I think there's some merit to proposals to adjust certain parts of the income tax to regional cost of living,” Jurow Kleiman said.