They may not be crunching all the numbers associated with health insurance, but folks whose incomes are three to four times the federal poverty level may be doing enough math to decide they'd rather pay the penalty for not having coverage than pay the premiums required to have exchange coverage.

Avalere released an analysis of the pay-vs.-penalty scenario established by the Patient Protection and Affordable Care Act, and theorized that one reason individuals with certain incomes continue to resist purchasing coverage is that the mandate's going-bare penalty is substantially lower than annual premiums for insurance.

Avalere notes that this sort of decision making is flawed, since it doesn't take into account the savings those with insurance may realize if they do require medical care. But particularly with those in their 20s, paying the penalty instead of buying coverage is a choice many are making.