Do you ever buy food when you're at work? A phone charger? Batteries? Clothing items? Toiletries? A crashpad?

Do you have any of these things accessible in your home?



That's what per diem is. It's reimbursement in recognition of the fact that spending half of your life on the road costs money. Money that perhaps you wouldn't have to spend if you were home every night. It is "income," in the sense that it's money coming in. However, it's not what should be classified as "wages."