See more of the story

Steve Ballmer, the former chief executive of Microsoft, knows more than a little about numbers. He's looked carefully at government spending and arrived at an unexpected conclusion.

"Government spending is more efficient than I thought," he said in a telephone interview. As for the 24 million Americans employed by government at all levels, he says, "I look at that and say, 'yeah, yeah' and most of that is good: firemen, policemen, soldiers, teachers."

The tech billionaire has launched a new product, USAFacts, an interactive website that compiles data to analyze how taxpayer money is actually spent. Still a work in progress, it assembles information from myriad government sources at the federal, state and local levels into one accessible place.

Ballmer doesn't bring an ideological or policy agenda to the project. He's trying to capture the spirit of the late Sen. Daniel Patrick Moynihan, D-N.Y., who famously observed, "Everyone is entitled to his own opinion, but not to his own facts."

Credible data are essential to policymakers. There may be a strong case for reining in the growth of federal entitlements such as Social Security and Medicare, but data show that it can't be done by resorting to the politician's standard pledge to dismantle bloated bureaucracies.

"Actually, transfer programs are run very efficiently, with not a lot of overhead costs," Ballmer said.

A particular interest of the former Microsoft CEO and his wife, Connie Snyder, is economic opportunity and mobility. Separately, they are planning initiatives to address intergenerational poverty. One conclusion Ballmer draws from the data he has seen so far is that government investment in improving opportunities for less-fortunate Americans "is much lower than I would have thought."

The data USAFacts assembles — a searchable compendium of information that's all available elsewhere — should help inform public-policy debates.

Take tax reform. USAFacts makes it easy to see that liberals who argue that there are gobs of gold to be mined by sticking it to rich people and corporations may be deluding themselves.

"You're not going to balance the budget with corporate tax reform," Ballmer said.

The data show that of all government revenue raised in 2014 (the latest year for which complete state, local and federal figures are included), corporate income taxes contributed only a little over 7 percent.

As Congress debates tax changes, it is instructive to look at how the benefits from current deductions tilt to the affluent. The home-mortgage deduction, depicted as the lifeblood of middle-class mobility, provides an average of only $84 a year for the middle-earning fifth of taxpayers and $373 to the next-highest quintile. For the top 1 percent of earners, the average annual benefit is almost $7,000. Write-offs for charitable deductions and for state and local taxes help the richest taxpayers even more.

The numbers also make it clear why there was such an uproar over the recent Republican efforts to dismantle Obamacare. Of the $157 billion Americans spent in 2015 on nursing-home costs, more than 55 percent was picked up by Medicaid or Medicare, with only a quarter paid by private insurance. Three-fifths of the beneficiaries of Medicaid, which Republicans sought to slash, are people with disabilities or children.

It's interesting to browse USAFacts for numbers known to health care professionals but jarring to casual observers. Consider these: 19 percent of Americans are at risk for depression, 16 percent for binge drinking and 30 percent for obesity.

More familiar is data showing that violent crime has been cut in half over the past quarter-century. But there are surprises there, too. If you think violent crime is most pervasive in the big cities of the Northeast, you're wrong. It's the South that's the worst danger zone; in 2015, it had 407 violent crimes per 100,000 people, compared with 313 per 100,000 in the Northeast.

Ballmer has enlisted scores of geeks, economists and statisticians who continue to develop more useful stuff. For example, they're doing state-by-state comparisons and they plan to expand into global factual perspectives.

It's an interesting start, paid for by Ballmer with the hope that agreement on facts might create common ground on policy. In the era of President Donald Trump, that's taking on quite a challenge.