Five Second ... Roberts

He asks "What is economics good for?" but is really trying to convince people that economics is a lot more like biology than physics. This is an exceptionally reasonable thought. Among his comments:

We do not expect a biologist to forecast how many squirrels will be alive in ten years if we increase the number of trees in the United States by 20%. A biologist would laugh at you. But that is what people ask of economists all the time. ... So the fact that economists did not foresee the Great Recession with any precision and have failed to model accurately the recovery does not mean that economics or even macroeconomics is worthless. My claim is simply that we should recognize the limits of reason in analyzing complex systems ...
So what is economics good for? It’s good for organizing your thinking. It helps you know where to look for causal elements even if we cannot measure their precise contribution or how to relative weights of factors that pull in opposite directions. Economics helps us understand ... relationship[s between complex variables holding all else constant] . ... But they do not reach the level of what the media expects economists to be able to explain. ...
Perhaps most importantly, economics can often remind us of the full range of effects of a particular policy, what Bastiat called the seen and the unseen. This is very valuable. Is it science? I don’t care. It’s a very powerful way of organizing your thinking about what happens when something changes in a complex system. Economics inevitably makes you aware of unintended or what might better be described as non-obvious consequences of a particular change.