An invaluable source of information on transportation is Reason Foundation analyst Robert Poole. In his latest post, dated May 13, Bob Poole writes: The ULCCs [ultra low cost carriers] continue to grow and are among the world’s most profitable airlines.

In a Wall Street Journalop-ed, “America Needs an Alternative Maximum Tax,” John Cochrane proposes a new kind of tax that caps the amount that people would pay in taxes to prevent indefinite tax-rate hikes. He asks, “How much is the most anyone should have to pay? When do taxes indisputably start to harm the economy and produce less revenue—when government takes 50% of people's income? 60%? 70%?” If there is a maximum amount that an individual pays, then once past that cap they wouldn’t pay any further federal income tax for that year.

Milton Friedman explains what happened when federal tax rates actually reached seventy percent over fifty years ago. As tax rates go up, taxpayers have more of a reason to avoid paying those taxes. Loopholes go hand-in-hand with higher tax rates, which is why lower rates on a broader base of income leads to a more equitable system.