1. The economics of taxi tipping.2. Best Chris Blattman non-fiction reads of last year.3. Penelope Fitzgerald at age 58.4. Austin Vernon on why nuclear power is stagnant.5. In a Gallup survey, Americans seem to be reading fewer books.6. "Across Congress Members, emotionality is higher for Democrats, for women, for ethnic/religious minorities, for the opposition party, and for members with ideologically extreme roll-call voting records."