If shouting was needed, I would.
The trouble with kids and parents today, I think, is that the parent is trying to be a best friend rather than a parent.
Working in retail, I see haphazard parenting every day.
Usually, shouting is not called for... Just a withering look, or calm but firm words do the trick.
Often, kids respond more favourably to an unknown adult rather than a parent if they are not in a home situation! 😀