The pay gap, from the survey that measures it
The Bureau of Labor Statistics publishes median usual weekly earnings for full-time workers aged 25 and over by highest qualification. For 2025: $770 without a high school diploma, $966 with one, $1,135 with an associate's degree, $1,578 with a bachelor's, $1,876 with a master's, $2,294 with a professional degree and $2,307 with a doctorate.
The bachelor's premium over a diploma is $612 a week — $31,824 a year. The 2025 figures average eleven months, because the survey was not collected in October during the federal government shutdown.
Worked example
($1,578 − $966) × 52 = $31,824 a year
The cost is mostly not tuition
Four years of full-time study means four years without a full-time wage. At the high school median that is $966 × 52 × 4 = $200,928 of forgone pay, against $100,000 of tuition and fees in a typical worked case.
So the real decision is about $300,928, not $100,000. It also explains why part-time study, employer sponsorship or a funded program changes the answer so dramatically: they remove the larger half of the cost.
Payback, NPV and return
At $31,824 a year, a $300,928 cost is repaid after 9.5 years of work. Over a 40-year career, discounting every amount at 3%, the net present value is about $385,148 — and the internal rate of return, the discount rate at which the degree merely breaks even, is 9.0% a year.
Three numbers, three questions. Payback answers how long you are exposed. NPV answers how much value the decision creates in today's money. IRR is the one to compare with other uses of the same money and years.
Unemployment belongs in the comparison
Median pay assumes you are working. In 2025 the unemployment rate was 2.8% for bachelor's holders, 4.3% with a high school diploma and 6.1% without one; doctoral and professional degrees were under 2%.
A lower chance of being out of work is part of the return and is invisible in a pay-gap calculation. It is also cumulative: spells of unemployment early in a career depress earnings long after they end.
What the medians hide
The BLS figures compare people who hold each qualification, not the same person with and without it. People who complete degrees differ in ways that also raise earnings, so part of the gap would exist anyway — economists spend careers trying to separate the two.
Field matters more than level for many students: the spread within bachelor's degrees is wider than the gap between a bachelor's and a master's. Replace the medians with realistic figures for your field before trusting any result.
Making the decision concrete
Use your own numbers on both sides: the actual net cost after grants and scholarships, the realistic starting pay in your field, and the interest on any loan, which is a real cost the premium has to cover first.
Then test the assumption that matters most. If the degree still pays back within a decade when you use conservative earnings, the case is robust. If it only works at optimistic earnings, that is worth knowing before signing.
Common mistakes
Counting tuition and ignoring forgone pay.On a four-year degree the pay given up is usually the larger number.Using the average graduate salary for your field.Medians span all fields; the range inside one degree level is enormous.Forgetting loan interest.Borrowed tuition costs more than its sticker price, and the premium has to cover the difference.Reading the premium as causation.Part of the gap reflects who completes degrees, not what the degree adds.