Thanks all. I should have been more specific in that both earners will take the standard deduction, no kids, and live in New York City. For NYC residents, there's a NYC education. credit (line 69a) that phases out after $500K. So if both earners are under $500K, they each get the credit whereas combined they exceed $500K and do not get the credit thus the desire to file separately. It amounts to about a $2,000 savings.
