born_yesterday: The physical sciences rely on theory being affirmed by experimentation. Can't economists point to examples of the implementation of a law and the consequences that follow? I'm guessing they can't, or that's where arguments arise, due to it being an open system with outside factors.

I always explain it like this:

The laws of economics are constructs invented by man to explain, predict and record collective human behavior. What that means is that economics is a number-crunching science much like physics, filling in values and numbers and formulas in an impossibly massive equation. Unlike physics, however, the mathematics of economics don't always work the way we think they will because they are subject to human farking behavior.

So we don't actually know what that equation looks like. We have general ideas of what parts of it look like and how it operates, but no one understands the complete, big picture to mathematical clarity, such that when we make small adjustments to the equation like changing interest rates or deregulating investment brackets, the results surprise us. Because they're almost nothing like what we predicted would happen. Not even supply and demand works the way it should.

Economics is simultaneously a hard and soft science. The changes people make to the great economics algorithm are always blind, usually self-serving, and won't work the same way forever.

There are men who come forth every now and then -- Keynes, Friedman, Greenspan, etc -- who propose theories and write treatises on how to manipulate the equation to make good things happen, and people put these theories to the test...and the theories always get things temporarily right and partly wrong, but no theory ever gets it completely right.