It doesn't take much more than a google search to find substantiation for the claim. https://www.politifact.com/global-news/statements/2016/mar/23/gayle-smith/

It doesn't take much more than a google search to find substantiation for the claim. https://www.politifact.com/global-news/statements/2016/mar/23/gayle-smith/did-we-really-reduce-extreme-poverty-half-30-years/ https://www.politifact.com/global-news/statements/2016/mar/2...