FOR an aspiring MBA, one of the main factors when choosing a school is the opportunity for career advancement—and a juicy pay rise. But the return must be weighed against the high cost of the investment. A full-time MBA programme at the biggest American institutions costs around $134,000 for the typical two-year course.

The return can be substantial. On average, alumni at the 100 schools in The Economist’s latest ranking of full-time MBA courses saw their average pay rise by 79% from pre-MBA levels, excluding bonuses. And the most prestigious schools tend to offer the largest payoff in absolute terms. Freshly minted MBAs from venerable American schools such as Stanford and Harvard earn an extra $52,000 a year in their new jobs. The courses also attract the brightest students. The average test score in the GMAT, the de facto entrance exam, is 675 for all schools, around the 82nd percentile. At Stanford, it is 737, in the 96th percentile. Students at elite schools also earned more to begin with. Entrants to the University of Pennsylvania’s Wharton School of Business, who tend to work in finance, are already making over $100,000 a year. But for Wharton graduates, starting from such a high baseline makes it harder to achieve additional big gains: their post-MBA salaries were only 29% above their incomes before entering, though that was still sufficient to rank third overall in earnings after graduation.

MBAs can make more of a difference for potential students whose current incomes are well below six figures. The largest boost is seen at Michigan State University’s Eli Broad College of Business. Students there earn just over $100,000 a year when they enter the workforce after graduation—a pretty standard post-MBA salary. However, that represents a 200% increase on pre-MBA income of $34,500. European schools such as HEC School of Management in Paris also provide good value. The full-time course there lasts 16 months, and its fees of $67,400 are around half of those charged by its American counterparts. Salaries for graduates are supercharged by the greatest amount in absolute terms: $71,600, or a 150% increase. If one chooses wisely, an MBA at the right school can be an investment worth making.