How many / what percentage of people stay in the consulting area after several years?
It varies from firm to firm, but not many. Typically at these firms, about one in eight people make it to the “Associate Partner” or equivalent role, which is about five to six years into your consulting experience on average (if you start at the entry level).
Most people leave either after just becoming an “Engagement Manager” or equivalent. The people who do stay and go on to become partners are people who absolutely love consulting, the impact they are able to make in their role, and the problem solving aspect of the role. The most common amount of time that people stay in consulting is two to three years on average.