It works and it works well when you stick to it. Your kids actually emotionally mature faster, although the downside of this is that they get dumped on by teachers and community peeps to "help" and tend to get overcorrected or berated to the point of shredding their self esteem when they do make a mistake because "I just can't believe he/she would DO that? He/she is so mature for his/her age!" But, they're still the age they are,.and precociousness is rarely 100%.

They're calmer. Fewer tantrums and meltdowns all around.

They're more engaged in the family from earlier on. Looking for ways to help out and all that. They learn to negotiate, which is a crucial life skill. Kids of authoritarian parents can't negotiate worth a damn. Less anxiety, more confidence.

In answer to your question, the parents do have to be prepared to let the child suffer the consequences of their belligerence. But, like Michelle said, if you start in infancy and this is just how things have always worked at your house, then you're not going to be looking at anything overly dramatic.