Should we pay coal miners to go to college?

In recent decades, many manufacturing workers in developed economies have lost their jobs, replaced by robots or cheaper imports. One option is to try to get those jobs back. Another is to retrain them to acquire skills that are in demand. But does it really make sense to send displaced manual workers to college? Chicago Booth's Anders Humlum talks about his research on retraining injured workers, which suggests that paying them to go to college reaps big returns. Is the same true for workers who lose their jobs to automation or trade?