The title of this post is the title of the paper, and very much not a statement of my opinion. The paper explains how. The questions that immediately spring to mind are 'effective for what?' and 'compared with what?' The answers from the paper are that it is effective (ish) for making children behave the way you want them to behave, if done in the recommended manner for a limited subset of contexts and people, compared with explaining to kids why their behaviour is unacceptable. Sigh.

Behaviourist approaches do often work as a way of producing the desired behaviour - that is their appeal and that is their point. They do not work at all well when compared with alternatives (explaining is only one of thousands of alternatives, the choice of which depends entirely on context), and they almost always have extremely undesirable side-effects. There are many subsidiary lessons that punishment teaches, including that you should obey those with more power, that you are less worthy than those with more power, that forcible manipulation is an acceptable thing to do to other people, etc. The same applies to rewards.

When I was young, untutored, and overwhelmed with the hassles of parenthood I did sometimes use punishment for my kids in much the same way that this research recommends as well as, occasionally, in anger. I am not proud of that. I think it is entirely understandable but it is a thing to be ashamed of, not to be celebrated. It is a lazy, short-termist short cut that has far more unpleasant side-effects than the benefits it brings. There is always an alternative and, though it may take longer, may be uncomfortable and it may take more patience, that alternative is almost always better in the long run. If we treat children like dogs (and behaviourist methods aren't even that great for dogs) they will likely grow up obedient - unless they react against it, which is a strong possibility - and, like dogs, if we let the leash slip or they spot a way to avoid punishment while doing something bad, they are likely to take it. Even if they don't, if the only reason they don't do the bad thing is habitual fear, the world will be a much sadder place.