The Gates Foundation is also dedicated to improving education and he hopes for more innovation in the area of teacher evaluation and improvement. Gates also expects the foundation to become more involved in online education. As higher education becomes prohibitively expensive, Gates said, he believes that through "online techniques ... education can improve a lot"
"I'm an optimist," Gates said, "but only because we put money into innovation."
Investment in education is one of the most important steps the government can take to improve the economy in the long-term, he said.
Education is "the most important thing for how competent our country is and how equitable it is in the decades ahead," he said. "I think education is a great example where the president said there need to be changes ... he picked a secretary of education who's going to give out money to innovators."
The foundation has begun investing significantly in innovations to increase agricultural productivity for poor people around the world. Wealthy governments' aid for food security actually declined from $8 billion in 1984 to $2 billion in 2007, Gates said in his letter.
Gates is also innovating in his own life. Gates published an essay this month on climate change for the Huffington Post, and started a new Web site, gatesnotes.com, which focuses on the work of his foundation. He has even joined Twitter, and tweeted for the first time last week.
"I like to get feedback if people disagree with how the foundation is taking all these resources," he said. "If people have ideas that we could be spending it better, I want to get that.
"It's a new experience for me," he said. "It's been fun so far."