Source: Casey B. Mulligan, National Bureau of Economic Research, NBER Working Paper No. 19366, August 2013
From the abstract:
Measured in percentage points, the Affordable Care Act will, by 2015, add about twelve times more to average marginal labor income tax rates nationwide than the Massachusetts health reform added to average rates in Massachusetts following its 2006 statewide health reform. The rate impacts are different between the two laws for several reasons, especially that: the populations subject to the two laws are different, the Affordable Care Act’s employer penalty is an order of magnitude greater, before either reform Massachusetts had already been offering more means-tested and employment-tested health insurance assistance than other states had, and the subsidized health insurance plans created by the Massachusetts reform were less substitutable for employer-provided insurance than are the subsidized plans to be created nationwide next year.