JUDY WOODRUFF: Almost all of us have wondered at one point or another about the taxes we pay: Where does the money go?

Former Microsoft CEO Steve Ballmer not only wondered. He decided to make the information available in the form of a new public research tool.

Last week, Ballmer launched USAFacts, an interactive Web site listing revenues and expenditures at all levels of government federal, state and local, all of it free to the public in digestible, searchable form.

I spoke yesterday with Mr. Ballmer, who is also the owner of the Los Angeles Clippers basketball team, about his latest venture, and I started by asking why he wanted to do this.

STEVE BALLMER, Former CEO, Microsoft: Almost three years ago, when I retired, my wife and I were talking about our philanthropic work and how does one help give opportunity, particularly to kids growing up in very disadvantaged situations.

And my initial kind of sense was, the government does that primarily, and what we should mostly do is pay our taxes. My wife said, no, I don't think that's quite right for us. We need to do more. We can do better.

But it got me kind of rummaging around in government data. And I soon found that, as good as the search engines were, it was really hard to bring together not just a picture of what was going on with disadvantaged kids, but how all the money was spent, not just at the federal level, but at the state and local level, not only to target kids, but then you have to understand what the tradeoffs were.

And that's how I got started really working on USAFacts.

JUDY WOODRUFF: So, what does it tell you that somebody can't find someplace else easily?

STEVE BALLMER: Well, remember, we use all government data sources, so everything else is findable. I'm not going to pretend we invented that much.

On the other hand, what we have tried to do is organize things in some sensible ways. We used the Constitution as the purpose of government as our organizing framework. Businesses have to have an organizing framework when they report to their shareholders. It seemed that's the most natural framework to use for government.

We found a few, two to three — three to four areas underneath each one of the preamble of the Constitution points, and so you have kind of a holistic view, not only of where the money is coming in, but where the money is coming out, and at least as well as they're measured today, what kind of impact government may be having or at least what's going on in the areas in which government focuses.

JUDY WOODRUFF: What do you say to people who — these days, a lot of people say they don't trust government, that they don't believe the information, the data that government puts out? What do you say to them?

STEVE BALLMER: Well, I would say, look, it's the best thing we have. It's the best data. It's created by professional people.

If I was in government and running government, I think I would use the government data, because I wouldn't know where else to look, quite frankly. And if I didn't like that data, I would work hard to make sure it got better and better and better, whether it was at the state or local or federal level.

People may have skepticism. I'm not one of those folks.

JUDY WOODRUFF: What is an example, Steve Ballmer, about information that you find on this site that you think is important and exciting?

STEVE BALLMER: Well, I will just give you one example of something that I found interesting.

You look at homeownership percentages in the United States. And off the top of my head, I want the say they run around 60 percent of people own a home. It might be plus or minus a little bit.

You look at the mortgage interest deduction, which is designed, I think, to promote homeownership, and then you can look at what percentage of that mortgage interest deduction amounts are going to people in the bottom 20 percent by income, the next 20 percent and so on?

And one might ask the question: Is the mortgage interest deduction doing a better job, a worse job, if it's supposed to promote homeownership and savings? Because home ownership is the biggest form of savings in this country. Different people will look at that data and draw different conclusions, but that's just an example of the kind of thing you can pull out of USAFacts and develop a point of view about.

JUDY WOODRUFF: So, does this project answer all your questions about, what's government doing for people, or are there many, many more questions you have that you still can't get answers to?

STEVE BALLMER: Well, there are many, many more questions, some of which we think we can get answers to.

The data is out there, but it is going to take more work to pull together and put in a comprehensible form. We can tell you, for example, what reading proficiency is for fourth graders across the country, but it would be interesting to look at that in the state of Washington or Mississippi or California. That kind of data needs to be added in.

The data we have is not always very current. Some of that is government data can be a little slower to get published. But some of that is state and local governments publish their data, and then there is a process today of rolling that up at the federal level that takes quite a while.

JUDY WOODRUFF: Two other quick things.

One is, I saw there are several — there have been several other attempts over the last number of years to set up a site like this with information accountability. Many of those have had a hard time staying alive. How committed are you to keeping this going?

STEVE BALLMER: I'm very committed.

It's — we have a philanthropic interest, my wife and I. And while we don't choose to use, you know, sort of a tax deductibility on this project, to me, it's kind of a civic opportunity. Hopefully, people find it of value.

We will stick with it. And we're very focused in on outcomes for government with respect to the amount of tax that goes in and the amount of expenditures that go out.

JUDY WOODRUFF: Steve Ballmer, thank you very much.

STEVE BALLMER: Appreciate it, Judy. Thanks very much to you.