There's very good evidence that being overly punitive for a crime reduces how often people will self-report. It's not a hard concept.
Start throwing people in jail and fining billions of $ and you will very quickly see the number of "incidents" drop. You will never learn if it's because they truly are happening less often.
What should I look at for such evidence? If something is highly regulated and controlled then things would be quite different from today, not sure there wouldn't be reports of failures of containment, for example, if they are mandated including any rquired monitoring.