Countries that borrow at spreads lower than their fundamentals justify — because investors have taken a bullish view — are more likely to run into trouble later. Pricing the sentiment out of past spreads cuts the error on medium-term GDP growth forecasts by up to 15%.

Five case studies in economic fragility — Libya and Yemen in conflict, Iraq and Somalia recovering from it, and West Bank and Gaza — on what fragility does to an economy and what policy can still reach.

The Maghreb trades less with itself than any other regional bloc on earth — under 5% of total trade. The paper traces that to uncoordinated national policy and restrictions on trade and capital, and sizes what integration would be worth.

Separating a coach's effect on scoring margin from the roster he was handed. The model behind the NBA Coach Effects page above.

The short version of the Maghreb integration paper, written for a general reader.

An early piece, written in Beirut, putting numbers on what the war next door was costing Lebanese trade, tourism and public finances.