We have had a lot of people working for us who need more income than they can earn working only one job.
Even if they are paid what is considered top wages, it can still be tough to make ends meet. I know guys who work two jobs and their wives also work and they are still just getting by in the face of the ever-rising cost of living.
I've never had a problem with guys moonlighting as long as they are able to do the work I need done. I have never felt I had the right to forbid anyone from working somewhere else, especially if I was not prepared to pay them as much as they needed or wanted.
But sometimes it can become a problem because it's easy for a guy to get burned out. We all need downtime to recharge. Working 12 or 16 hours a day can wear thin if a guy is not in tip top shape. When a guy gets so tired that he cannot get to work on time or his performance or level of production is adversely affected, that becomes a problem.
It may not be possible to pay a guy more so that he does not need additional income. And asking him to quit the second job might result in the same problems that burnout can cause. Im open to suggestions for a solution.