Doctor, Teacher, Civil Servant: Stable Income as a Parallel Line

Doctors, teachers, civil servants — their income follows a slowly rising parallel line; you can work at it for a long time, even a lifetime. Take software engineers, for example. Their income curve is more like a parabola: it shoots up to a high point early on, then drops off steeply. What awaits them down the road is career transition, a pivot to a different field, or unemployment.