Republican Presidential candidate John McCain’s health care plan would likely have little impact on the number of uninsured Americans, according to a study co-authored by Harvard School of Public Health professor Katherine Swartz.

Swartz and her three co-writers concluded that, within five years, this number could in fact increase.

“Moving toward a relatively unregulated non-group market will tend to raise costs, reduce the generosity of benefits, and leave people with fewer consumer protections,” the study found.

The group focused on McCain’s proposals to introduce a tax on insurance premiums paid by employers, to institute an individual refundable tax credit, and to move toward allowing intra-state policy purchases.

The authors wrote that they felt Obama’s health care plan had been scrutinized during the primary season but McCain’s had not been subjected to academic review.

“Obama’s plan is more likely, right off the bat, to have more people covered by health insurance,” said Swartz, noting that without regulation only young, healthy people will be able to get insurance coverage.

David M. Cutler, a professor of applied economics who is currently an adviser to Obama’s presidential campaign, said he believes his candidate’s proposal will show more long-term results, cover almost every citizen, and do much more to modernize health care by investing in information technology.

“People don’t get the care they need,” he said. “And when they do get it, it’s too expensive.”

Swartz said, though, that the current economic crunch could lead to some speed bumps in the march toward health care reform.

“I think it’s hard to tell today, without knowing what Congress will approve,” she said. “Feasibility depends on political will.”

According to Howard K. Koh, a professor of Public Health and former Massachusetts Commissioner of Public Health, Obama’s plan calls to mind some of the main facets of Massachusetts’ own 2006 reform.

“Senator Obama’s plan resonates with many of the themes of ‘shared responsibility’ that rallied Massachusetts behind a new 2006 health care reform law...whose results have been new health coverage for over 430,000 previously uninsured individuals,” he said.