[logicchains]

>if college education produces a public good (a more competent workforce)

It doesn't achieve this; the % of college graduates has vastly increased over the past few decades, but this hasn't contributed to any significant improvements in standardised measures of graduate knowledge or intelligence. From a business perspective the primarily usage of college is as a filter, a proxy for intelligence and willingness to follow instructions, but its usefulness as a filter has been steadily decreasing as it becomes easier and easier to attend and graduate from college.