Bill Gates and Warren Buffett are asking their fellow billionaires to sign a giving pledge to give away half of their fortunes.

One of those who's doing so is David Rubenstein.

I don't have the money that Bill Gates or Warren Buffett has, so I had to pick projects where I think my amount of money will make a difference.

So that's what I try to do. Most people when they start giving away money, probably give it to their Alma mater, or other education institutions.

'Cuz everybody wants people to be smarter and better in form. Also people tend to do things related to health

because health is something everybody wants everyone else to have - good health and longer life. And so I've given away a fair amount of money at education and health,

but I've tried to find certain things in the Washington area, where I lived and where my money was made, that I think will help the city of Washington and help our country.

I've called the patriotic philanthropy. By that I mean trying to remind people the legacy of our country, the great problems you had in the beginning,

and the great challenges we've overcome, what really made our country so great.

And so I'm trying to focus on preserving historic documents like the magnet card of the Declaration of Independence, the Emancipation Proclamation,

or repairing monuments like the Washington Monument, or helping to renovate the Kennedy Center or things with the Natural Archive or the Smithsonian.

as a way of encouraging other people to say: yes we have an obligation to this country, to give back to the country.

So it's good to give to your alma mater, it's good to give to a hospital, but also remember the country that you're from,

and try to give back to the country and make the country a better place than it was before.

And how do you decide what's the most effective of the philanthropic work that you do?

Nobody really has a perfect metric. In the business world we have a metric - profit and loss, and you can know whether you're doing well or not.

In the philanthropic world, there's no perfect metric. Now some people have very complicated ways of analyzing the impact of what they've given.

And they're very careful and dutiful about it. I don't have a staff, I don't have a foundation. I tend to give money to organizations I trust and people I trust,

and I get reports. And I try to monitor myself. But there's no perfect way, and generally I'm happy with what I'm done.

Maybe 90% of the time I'm happy and 10% I'm not happy, then I just don't give more money to people that I'm not happy with.

But there's no perfect way, and I don't wanna obsess over the metric so much so that the people don't really wanna have my money,

or they roll their eyes when they see me coming along as "I'll give you money", but I wanna count on metric every week, I want the report.

I tend not to do that, but I'm not saying others who do that are terrible. I just don't do it myself.

Well, in private equity, I have been a specialist in raising money for my firm.

So that was my area expertise. I really wasn't the investor, I was the person to ask money.

So I do think that I've taken that skill set, to the extent as a skill set, and try to apply it to philanthropic area. So I'm willing to ask people for money.

Very often people in my situation don't like to ask other people for money, or they don't wanna cheer a capital campaign.

But I'm quite willing to do it because I realized that it helps more organizations and someone like me as willing to give money but also ask other people for money.

And what about advice for your earlier self when it comes to how to do the philanthropic work, should you started earlier, done things in a different approach?

What would you say to the young, David Rubenstein?

Yes. When I was young I came from a family very modest means, so what I wanted to do is to rise up and actually make some money.

And when I finally did make money, I didn't realize how much I was fortune enough to make. But I didn't really give money away earlier on,

maybe I should have, and maybe I should have made it a part of my DNA early in life to give away a percentage whatever I had.

So I regret very much not doing this much before my 50s. I wish I started at my 20s, 30s, and 40s, but I really didn't.

And my hope: my children will do things differently, and I hope younger people will get involved in philanthropy as part of their life,

and not as part of an add-on to after a successful business or professional career.