The "bad and better" mental model works well in many scenarios. Particularly where people tend to become hyperbolic and think in only absolutes. Rosling used

The "bad and better" mental model works well in many scenarios. Particularly where people tend to become hyperbolic and think in only absolutes. Rosling used to work in Mozambique, the poorest country in the world at that time. In his first year there he was the only doctor for a population of 300,000 (!) people. He writes further: in my second year, a second doctor joined me. We covered a population that in Sweden would have been served by 100 doctors, and every morning on my way to work I said to myself, "Today I must do the work of 50 doctors."