Intro -- Contents -- I. INTRODUCTION -- II. BASIC FRAMEWORK -- III. BASELINE CALIBRATIONS -- IV. DOMESTIC ADDITIONAL EFFORT, POVERTY TRAPS, AND "TAKEOFF" -- V. EXTENSIONS -- VI. CONCLUDING REMARKS -- REFERENCES.

We identify structural breaks in economic growth in 140 countries and use these to define ""growth spells:"" periods of high growth preceded by an upbreak and ending either with a downbreak or with the end of the sample. Growth spells tend to be shorter in African and Latin American countries...