SMITH BRAIN TRUST — In the same way that Uber and Lyft turn regular cars into taxis, Airbnb has made every house on your street a potential hotel. Thanks to an accounting trick at Airbnb, most of the side income that hosts receive goes unreported to the IRS. Many host families will take this as an invitation to evade taxes on April 15. But Smith School professor Leslie Mostow, a CPA with more than 50 years of tax preparation experience, warns that IRS auditors have tricks of their own.

SMITH BRAIN TRUST -- Personal and corporate income tax laws are complex and expensive. The collective cost of tax filing, record keeping and the like is least $170 billion a year, says professor Peter Morici at the University of Maryland's Robert H. Smith School of Business. In a column today, Morici says other nations more efficiently rely on consumption taxes than income taxes. The U.S. system should shift in that direction, he says.