I love economics. It's the best way to win arguments that really shouldn't be winnable.
I guess I should say I like econometrics, as opposed to economics. Economics includes groups like the Austrian and Chicago schools, which rely very heavily on intuition, which is no way to win an argument. Your intuition is just as good as mine, and it's very easy to point that out. But for example, the argument of prostitution. Is it right or wrong?
Correct answer: it doesn't matter. We cannot stop it. It has existed since the beginning of time, and exists even in countries where prostitution is punishable by death. So, if it cannot be stopped, why have laws against it? People still kill, regardless of laws. So why bother outlawing that? But, then, we're comparing prostitution to murder, which is pretty stupid.
Moreover, countries without laws against murder are usually on the edge of coherency, and as such, the lack of the law isn't really what is causing murder; it's the lack of social order. Laws against murder and stealing sprout spontaneously from a social order because they're fundamentally necessary for that order to exist. Laws against prostitution hold no such honor.
Truly, prostitution frequently held the opposite stature in past civilizations. Frequently, prostitution was seen as a necessity for grown men, and that prostitutes did a public good. Even in modern times, during periods of war, the military tolerated and understood the job that nearby brothels performed.
Economics gives us the ability to develop a scenario and then seek out data. Just find the data and make your argument with that. Freakonomics had it right. Trying to argue right and wrong, or develop models to determine things gets you nowhere. Just find the data.