I think the answer most employers look for is general disagreement, but the reasoning for your answer is what is most important. If you disagree and think most people wouldn't steal, even if they could get away with it, your line of reasoning should be that you tend to think people are generally good and well-meaning, and that you'd like to be optimistic that people wouldn't be that way. When answering this way you must be careful not to come across as naive. You might follow up this response by mentioning that while you feel the majority would not steal, there'd definitely be some people who would be more inclined to shoplift knowing they could get away with it.
Honestly, I think you're backing yourself into a corner if you answer that you agree with the statement. While you may be able to come up with an extremely intelligent answer regarding why you agree, chances are the retail manager you're having the interview with is not a very intelligent individual to begin with. He or she is looking to weed people out with certain responses (in this case that you agree most people would shoplift). They only start to listen after you've given what, to them, is the correct response.
Their primary aim with this question is to predict internal theft. Internal theft (theft involving employees of the company) usually comprises about 50% of their shrink. By agreeing most people would steal given the chance, you're raising all sorts of red flags.
"Prepare for the worst. Expect the Best"
To me, that quote kind of sums up how you should answer this question.
"While I'd hope, and expect, that most people wouldn't steal even if they were guaranteed to get away with it, I'm not so naive as to think there wouldn't be some who would leap at the opportunity. Any sensible business model should embrace a philosophy that provides excellent customer service combined with a practical amount of caution. Customer service can be the greatest defense against shoplifting."
Lorem ipsum dolor sit amet, consectetur adipiscing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor
in reprehenderit in voluptate velit esse cillum dolore eu fugiat.
SHOW ANSWER