I use to be a retail security manager and I don’t see any problem with self checkout from a shrinkage standpoint when balanced against added convenience for honest customers.
Many years ago the FBI did a study and determined that for general retail stores in the U.S. a national average of 10% of the customers walking in your door did so with the intent of stealing something. 10% of them wouldn’t steal from you even by accident and the other 80% could go either way depending on circumstances.
For the professional thief self checkout is a non-starter. It’s more closely monitored than the easiest way which is just to walk in pick up what you want and walk out with it. They know that what gets you caught is looking suspicious so if you just act like you own the place no one pays attention to you, unless you’ve given them other visual queues. Also you just can’t get enough value or volume through a self checkout at one time to make it worthwhile.
For the casual thief there are enough deterrents in place to prevent most of them from trying to steal. Most of those deterrents aren’t real as sonicfox’s stories illustrate rather they are primarily psychological and designed to increase the level of apprehension thus deterring the armature.
Even when the honest mistakes and theft via self-checkout are combined they will not be significant compared the other much more prevalent forms of shrinkage when compared to added convenience to customers and lower labour cost.
I’m not sure about anyone else but for me self-checkout lets me shop like I’m at a convenience store, only with a much better selection.
