@spayurpets - The way the Economist presents the data is confusing, but I do not think that is case. The following is the output from the Economist website for Oberlin College, a noted Marx and Marxist school. Follow the math:
$42,751 median graduate income for an average college
Add:
$-5,503 impact of fields of study
$-5,454 Marx & Marley factor
$5,118 SAT scores
$3,856 all other factors
Equals:
$40,768 expected earnings at Oberlin based on the Economist multiple regression
$38,400 actual median income of graduates of Oberlin
$-2,368 Underperformance calculated by the Economist
They start with the $42,751 median graduate income, and clearly subtract $5,503 for fields of study (likely no engineering and light STEM), subtract $5,454 for Marx and Marley, add $5,118 for the high SAT scores and then add $3,856 for other factors. The total is the expected earnings from their model of $40,768. Oberlins actual median earnings are $38,400, from which they calculate Oberlin’s underperformance compared to their model of $2,368. In other words, Oberlin’s actual graduates earned $2,368 less than what their model predicted.
If Marx and Marley actual did positively increase the expected income, one would expect the figure in the Economist results to be positive, not negative.
If you do not believe that, compare the Marx and Marley adjustment with the SAT score adjustment. Oberlin is one of the most selective LACs in the country with very high average SAT scores. It is evident that higher SAT scores are associated with higher incomes. If Oberlin students were getting a positive $5,118 benefit from the high SAT scores, why would they receive a negative $5,454 adjustment for Marx and Marley if that were a positive category as well?
Have a Happy Thanksgiving.