Comment by lutusp | Hacker News Reader

Comment by lutusp | Hacker News Reader

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> A science is a method, not a domain or result or anything else.

No, this is false. Science is defined more clearly than this. Science is not a method, it is a set of rules for creating a method. Primary among those rules are a requirement for empirical evidence in support of scientific theories, and falsifiability -- meaning scientific ideas must be testable against reality, and those that fail the test must be discarded.

TL;DR: Science is more principle than method.

> ... one can approach economics or medicine or traveling salesman problem using the scientific method ...

By that reasoning, astrology is a science, because it can be studied using the scientific method. But this is not how science works. For X to become a science, scientific study must support the theories that define X. Explanation here:

http://arachnoid.com/psychology/index.html#The_Architecture_...

Economics is not a science.

Title: "10 reasons why economics is an art, not a science"

Link: http://articles.washingtonpost.com/2013-08-09/business/41217...

>By that reasoning, astrology is a science, because it can be studied using the scientific method.

exactly, one can do pure scientific study of correlation between that star position and people's lives and most probably would find zero correlation - it would be a valid (though practically useless given current state of science in related areas) scientific study in the domain of astrology. That domain happens to be full of non-scientific results and statements while has no useful non-trivial scientific results known. Thus people label the domain as 'non-science'. Economics has a lot of both.

The problem with rejecting economics' claim to be a science on the basis its underlying assumptions survive even as models based on them are usually out by a few percentage points (and under certain circumstances give counterintuitive results) is that you'd probably have to throw a lot of natural science with the bathwater. Physics is the exception rather than the rule for the accuracy and robustness of falsifiable predictionswhilst medics - like economists - are left with statistical tests, ad hoc explanations of confounding factors and a raft of exceptions that arguably falsify claims as uncontroversial as "drinking in excess is bad for your health". On the other hand, unlike astrology or homeopathy neither discipline is afraid of testing its assertions against a null hypothesis.

As I understand it there are several 'schools' of economics which use different models and which council different responses to the recent financial crisis - sometimes completely opposite responses.

I'd be more inclined to consider economics a science if, of the multiple contradictory models, all but one had been falsified.

Personally I don't consider social sciences to be real sciences for the same reason. If you want to say economics is a social science I would agree with that.

most economists are not very serious about testing their models. this is reflected in the way the subject is normally taught.

> The problem with rejecting economics' claim to be a science on the basis its underlying assumptions survive even as models based on them are usually out by a few percentage points (and under certain circumstances give counterintuitive results) is that you'd probably have to throw a lot of natural science with the bathwater.

Actually, it's a bit simpler than that. Sciences, and scientific theories, can be easily identified by the property of falsifiability. If a theory makes coherent, testable predictions, and if the predictions can be tested empirically, then there's a basis for falsification. Economics doesn't have this property. Many natural sciences do. For example, anything having to do with evolution -- very specific, very testable, and excellent at resisting falsification. Not that surviving falsification is required to call something science -- failed theories and fields are scientific in a sense, certainly more so than those fields that never test their theories.

> ... whilst medics - like economists - are left with statistical tests, ad hoc explanations of confounding factors and a raft of exceptions that arguably falsify claims as uncontroversial as "drinking in excess is bad for your health".

Yes, but those aren't really falsifiable, are they? One can argue that a failed test like that is equivocal, not a basis for casting out the underlying theory. In a formal sense, that prevents their being called sciences.

I have to say about modern medicine that it's rapidly moving toward being evidence-based. Many clinical practices from years past have failed more rigorous efficacy trials and have been cast out as a result. So I would call it science on the basis that its theories and practices are open to falsification.

> Economics doesn't have this property.

is sounds like it is an unfalsifiable statement for you.

> If a theory makes coherent, testable predictions, and if the predictions can be tested empirically, then there's a basis for falsification. Economics doesn't have this property.

The subject matter of economics certainly involves the kind of observable quantifiable results that admit of falsifiable hypotheses.

Its true that many of the interesting hypotheses offered in the field are falsfiable in principle but faced with significant pragmatic difficulties in conducting unambiguous tests which leads to the practical tests frequently providing ambiguous results, and that many of the practical-and-unambiguous falsification tests are unsatisfying (in that, while they could unambiguously falsify the hypotheses they are offered as tests for, they aren't differential tests wherein the result that fails to falsify one interesting hypothesis necessary does falsify a competing interesting hypothesis.)

This doesn't make economics "not a science". It makes it a difficult science.

(The fact that the questions in the domain are often important to public policy and other decisions in which lots of people with lots of resources have vested interest also results in a lot of things in the field being oversold to decision-makers, but that's equally true in similarly salient physical science fields that don't face the same kinds of testing difficulties, and is irrelevant to whether the field is a scientific one.)

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