today a preview of the nuclear summit of the liggett key challenges to preventing nuclear terrorism. -- end a look at key challenges to preventing nuclear terrorism. wednesday, live from the white house, michelle obama, who has made fighting childhood obesity one of her priorities, will sit down with a c-span studentcam winner. his documentary was one of many submitted on the topic of childhood obesity. joining in the conversation will be other winners from around the country. that is at 11:00 a.m. eastern here on c-span. >> i know what the challenges, and we're in a unique position to go to work. what we need is to develop our road map so we can get it done. >> something about energy policy would like to talk about on your blog? at the new seize the library, you can search it and share it -- at the news c-span library, you can search for it and share it. cable cause latest gift to america. this year's student competition as some middle and high school students to create a five minutes to a minute video dealing with one of our country's greatest strengths or a challenge the country i

guest: i do nothing it did anything that you can liggett. it is difficult to predict the future -- you can look at. it is difficult to predict the future. back in the '60s, i remember economists felt they had all these economic models and they put every statistic they wanted into the great databases. they could match of what was happening in the present with the past. it turns out the models were very good if nothing changed. as soon as things change, the models were terrible. it is difficult to predict the future. host: republican -- republican line. caller: i have been an admirer of yours for many years. i think you are a great columnist. i just wanted to say -- hello? guest: i am here. i appreciate the praise. caller: of one to get your opinion of the health care bill -- i wanted to get your opinion of the health care bill and the promises that were made that this bill is deficit neutral and that it actually helps the deficit. i never believe those figures. i do not believe the numbers. i just wanted to hear your opinion. why does the new