Three essays won a contest on major AI challenges. First, Jassi Pannu outlines a $40–60 billion plan to end airborne disease transmission using far-UVC lamps and infrastructure. Second, Ege Erdil advises middle-power countries to boost growth through proven policies like strong property rights and low taxes. Third, Michael Li likens AI labs’ business model to Hong Kong’s MTR, suggesting labs buy up complementary assets to offset high CapEx.