Is krav maga a good self defense?

It's proven itself time and again in street brawls since the sport's revival in the early 1700's in Great Britain. The modern sport of boxing, was the only "self-defense" smaller kids had against bullies prior to the 1970's with the rise of the more "exotic" fighting arts (like Karate). In fact, a good 90% of World War II era males, know how to box, regardless of ethnic background.

Is boxing effective? Put it this way; in East Los Angeles, boxing gyms, and people who go there on a regular basis are avoided by street punks and cholos for a reason. In fact, in a bad neighborhood of a large city, the safest place in said bad neighborhood is likely the area around a boxing gym; even gang members don't mess with them. There are always stupid punks who try, but 90% of the time they almost always get beat up, and badly too. Street kids, gang members have their reputation for being very dangerous street brawlers, but, believe it or not even they will avoid provoking a boxing gym.