captioned by access.wgbh.org and ford. we go further, so you can. >> whitaker: what is this? you might think of heroin as primarily an inner city problem, but dealers are making huge profits by expanding to new, lucrative markets-- suburbs all across the country. i'm sitting here looking at you, and you look young and fresh. you're the... you're the girl

the giving pledge. ages range from 27 to 98. some inherited wealth, but most are self-made. their businesses range from improvement. combined pledges so far? over a half a trillion dollars. what conditions are there? i mean, can they say, "yes, i'm with you. i'm here. but i want to give it to this institution or that institution." >> buffett: we don't care what institution they give it to. >> bill gates: yeah, in fact, we're not endorsing any flavor of philanthropy.