— Reihan Salam responds to Ezra’s column on the effect Ryan’s budget will have on social mobility.
— Speaking of which, the party reactions to Obama’s budget speech seem like more evidence in favor of Ezra’s thesis on presidential polarization.
— A closer look at Rahm Emanuel’s plan to spend $7.2 billion on infrastructure in Chicago.
— “So we have New York entrenched as America’s first city, and Washington, DC increasingly its new ‘Second City.’ ”
— Annie Lowrey interviews Ngozi Okonjo-Iweala about why she wants to run the World Bank.
— How mass migration cushioned the Great Depression.
— Congrats to Ta-Nehesi Coates for winning the Hillman Prize in opinion and analysis.
— Every now and again, Earth gets a second (tiny) moon, scientists discover.
— The collapse of the Soviet Union was terrible for American mathematicians.