Self Checkout

I guess I get why people steal, but then do that many people steal? I've accidentally walked out of the store with something extra or gotten distracted at the checkout line and forgot something, but I've always returned to pay for whatever I missed. And large retailers have loss to theft built into their business model. I guess the question is are that many more people stealing in a self-checkout aisle?
strealing a frozen pizza or a can of green beans or a case of water or cokes isn't whats hurting them. Its gotta be the big ticket items, high priced items. If i had to guess, at Kroger its meat and Walmart its electronics.
I was at Walmart the other day, i got a pair of shorts on Clearance. the tag was $5. when i rang them up, they came up as $26. I had to wait almost 5 minutes for someone to help me because she was running at least 10 self checkouts by herself. It ticked me off, but i know it wasn't this poor girls fault. between having to keep an eye on that many registers and help a bunch of people who didn't know what they were doing, she was stretched thin.