His list of top good news stories in 2015 includes the following:
1. Africa Went a Year Without Any Polio
2. Neil Tyson Made a Stunning Case for Science
3. Global Health Innovators Won the Nobel Prize
4. SAT Test Prep Is Now Free for Everyone
5. Mobile Banking Exceeds Our Optimistic Projections
6. The Americas Have Eliminated Rubella
See gatesnotes for the full story.