You're not going to be very effective at the plate if you're up there worried about getting hit".
But basic economics shows that competition between employers for workers can be very effective at preventing businesses from misbehaving.
"The sunscreens in North America tend to be very effective at blocking UVB rays, but not UVA rays," she said.
Some airports may use birds of prey sounds — I don't find those to be very effective at all.
The academic literature shows that monetary policy can be very effective at reducing unemployment in situations like ours.
"We see gains in some states from reform efforts, and we see that resources, if they're properly targeted, can be very effective at raising achievement".
But threats can be very effective, at least when aimed not at children but at schools, school systems and states that have happily tolerated failure for decades.
Despite the higher support for stricter gun laws, many Americans do not think the changes would be very effective at deterring violence.
That said, I don't think it's realistic to expect the news media to be very effective at policing this kind of wrongness.
But, she adds, "basic economics shows that competition between employers for workers can be very effective at preventing businesses from misbehaving".
As one of them put it: "If you look like you are continually on the point of shouting, and a bit of a nutter, you can be very effective at getting things to happen.
