For many potential patients, 2014 started with a new title: insured. What this means and who it encompasses, however, is up for grabs.

As noted by the Wall Street Journal, progress has been shaky since the Affordable Care Act made its way through Congress, including the autumn spectacle in which Healthcare.gov left many applicants on the sidelines as it struggled to manage even a portion of anticipated web traffic.

Assessing healthcare reform’s impact requires hammering out a lot of what-ifs. Right now, for example, insurers told the Journal that web problems probably kept younger—and therefore healthier and less financially burdensome—customers from signing up for coverage. There is still time to sign up for insurance, which means younger, healthier patients who are putting money into a system they are not disproportionately drawing from can still join up and drive data in a new direction. At the same time, there have been reports of grumbling among the already-insured about rising deductibles, but how and if that discontent translates into a dialing up or down of healthcare-system use is one for the what-if pile.

At the same time, Health Affairs published in December yet another study that showed most Americans do not understand basic health insurance concepts like deductibles and data. The Urban Institute survey the researchers used essentially put all newly insured in the same context as a just-employed 20-something who needs to learn how insurance works and just how much coverage they need.

None of this data, however, anticipates how these factors will influence patient behavior and medical care consumption, and is a question that has bedeviled researchers since even before insurance became a universal requirement.