Heather McGhee is an expert in economic and social policy, and now chairs the board of Color of Change, the nation’s largest online racial justice organization. Her new book THE SUM OF US offers a powerful exploration of inequality and the lesson that generations of Americans have failed to learn: Racism has a cost for everyone—not just for people of color. But in unlikely places of worship and work, McGhee finds proof of what she calls the Solidarity Dividend: the benefits we gain when people come together across race to accomplish what we simply can’t do on our own.