(Photo: Frederic Courbet, Gates Foundation) 
 
 SAN FRANCISCO — Despite the sober tone of the times — tensions with Russia, the growing threat of terrorism — one altruistic husband and wife duo spies a gradual improvement in the state of the world.
– A bold prediction, courtesy of the Gates Foundation: The lives of people in poor countries "will improve faster in the next 15 years than at any time in history." That statement comes via the foundation's annual letter, published today, which makes some other "big bets." Among them: Polio will be eradicated by 2020, Africa's agricultural productivity will increase by 50% by 2030, and deaths of children under 5 will be cut in half by 2030, the Guardian and the AP report. Why are Bill and Melinda Gates so confident? Their foundation is celebrating its 15th anniversary, and the progress against inequity that they've seen in those 15 years is "very exciting—so exciting that we are doubling down on the bet we made 15 years ago, and picking ambitious goals for what's possible 15 years from now." In addition to polio, the foundation says guinea worm, elephantiasis, and blinding trachoma will be eliminated by 2030. There will also be a single-dose cure for malaria, a vaccine to prevent it spreading to mosquitoes that bite those with the disease, and a diagnostic test to reveal the infected, the Gateses predict. The foundation also foresees a rise in digital banking and online education and will push for gender equality. "We know that when women can participate equally in a country's economy, the GDP goes up 12%," Melinda Gates tells USA Today. (Help for the poor and inequality appear to be a hot topic, with Mitt Romney and Jeb Bush each taking on the issue, the New York Times reports.)