It has become a popular talking point: About half of all American adults, 46 percent, don't pay income taxes.

So who are these slackers?

It turns out this may be hitting a little close to home.

They're senior citizens.

And they're working families with children who make low incomes.

Those two groups account for three-quarters of the adults who don't pay income taxes.

The Tax Policy Center of the Urban Institute and the Brookings Institution looked into this issue.

So what would happen if all the loopholes were repealed?

Half of the adults who aren't paying income tax today still wouldn't pay anything thanks to personal exemptions and the standard deduction.

Credits are often the reason that people don't pay income taxes. Credits, by and large, were passed for noble reasons.

Credits for the elderly include an extra standard deduction and excluding part of Social Security benefits from taxes.

Credits for children and working poor include the child tax credit and the earned income tax credit. These are incentives for people to work and stay off welfare.

For those making less than $50,000 a year, credits for elderly, children and the poor are most important.

For those making between $50,000 and $100,000, child and education tax credits and itemized deductions remove the most from the tax rolls.

So the implication that a bunch of American slackers are not doing their fair share is not exactly accurate.

Of course, even when people aren't paying income taxes they are paying sales taxes, payroll taxes and fees. In Jacksonville, for instance, a typical JEA bill of $167 includes about $26 in government fees and taxes.

Defensive medicine
Trying to put a cost on defensive medicine is difficult. But the fact that physicians are ordering tests or medications for non-medical needs is well established.

Consider this poll of 824 physicians in 2003, reported by the American Medical Association:

- 93 percent said they engaged in defensive medicine. This could mean ordering tests, diagnostic procedures or referring patients for consultation.

- 43 percent used imaging technology when it wasn't necessary.

- 42 percent have restricted their practices to avoid potential lawsuits.

Finding a way to protect consumers from malpractice while avoiding defensive medicine is a challenge. One idea is that when physicians practice with certain commonly accepted procedures, they will be protected at some level from liability.

Infant mortality's importance
Keeping infants alive in the first year of life is one of the sentinel indicators of a nation's overall health.

Thus it is a concern that the United States has a so-so average among developed countries, ranking No. 40 in a listing of 193 countries from the World Health Organization. The U.S. is tied with Croatia.

The difference is that the United States has a major gap in infant mortality among African-Americans.

In Jacksonville, the infant morality rate for blacks is twice the rate for whites. Even so, the infant mortality rate has been declining in recent years here due to increased awareness and various programs.

Reducing medical costs
Nobody seems to be having much luck putting a damper on rising health care costs.

One of the major attempts involves "accountable care organizations," which ends the fee-for-service merry-go-round and gives physician groups set amounts for medical care. If costs are below a set target, the physicians participate in the savings.

An experiment involving 10 accountable care groups in some of the nation's most respected organizations has produced good results in quality but less exciting results on savings.

Gail Wilensky reviewed the results in the New England Journal of Medicine.

The demonstration began in 2005 with 10 large groups. The idea was to exceed savings of 2 percent and meet 32 quality goals.

By the fourth year of the project, all 10 groups met at least 29 of 32 quality goals.

But only two of the 32 groups were able to exceed 2 percent savings in the first year, and only half did so in three years.

In any case, these experiments need to continue because the nation can't continue to have health care rack up costs much higher than the inflation rate.

The United States spends at least twice per capita for health care than other developed countries like Japan or Canada, but our outcomes aren't nearly twice as good.

Good news for 'canes
The good news from the latest college rankings from U.S. & World Report is the meteoric rise of the University of Miami.

The bad news is the drop for the University of Florida.

While the University of Miami has soared nine spots to No. 38 in the national rankings, the University of Florida dropped 11 spots to No. 58.

When you look at the reasons for the changes in the rankings, several items come through.

For the University of Florida, there have been significant drops in state funding and in reputation.

President Bernie Machen said that the university is doing well in the areas it can control such as in graduation and student retention.

"The problem is the nation believes the state of Florida does not value higher education," he said in The Miami Herald.

The university has suffered a 25 percent drop in state appropriations in the last three years.