[dingfeng_quek]

You're not exactly describing the difference. I would say that:

1. We have statistical evidence from large numbers of SIMILAR people with similar tumors. Economic events tend to be highly dissimilar in terms of context (Great Depression? 1988 Savings and Loans Crisis? 1997 Asian Financial Crisis? 2008 Global Financial Crisis?), and only to be similar in terms of before-and-after on some narrow set of parameters. This makes prediction and counter-factual history for economic stuff really hard.

2. We also understand some of the mechanisms of how tumors work and affect physiology. These are founded upon a large body of knowledge of causation and empirics in medicine, chemistry, and biology. Economics lack a comparably reliable and large body of knowledge because of 1.

[yummyfajitas]

This makes prediction and counter-factual history for economic stuff really hard.

Exactly my point. We really have no idea what would have happened had the fed not intervened and allowed a normal bankruptcy to occur.

I'm not saying economists are lazy and stupid, I'm just saying they lack data, and that tatsuke's counterfactual (GDII) is not a very good one.

[tatsuke95]

>"We really have no idea what would have happened had the fed not intervened and allowed a normal bankruptcy to occur."

This is the fallacy: You really have no idea. That's not an insult. People who do this for a living, like, say, FRB economists, do know the consequences of letting bank runs occur and not providing liquidity during a crisis. It's well studied.

[tatsuke95]

>" Economic events tend to be highly dissimilar in terms of context (Great Depression? 1988 Savings and Loans Crisis? 1997 Asian Financial Crisis? 2008 Global Financial Crisis?)"

I'm not sure this is true, either. Financial crises are surprisingly similar [0].

[0]http://www.amazon.com/This-Time-Different-Centuries-Financia...

>"These are founded upon a large body of knowledge of causation and empirics in medicine, chemistry, and biology"

And what about new discoveries? What do they do then?

Some things are easy. Some things are new, you have little data, and have to make a best guess. Same as economics.