يك سؤال تكراري و چند ابهام-3/ چرا مي‌توان اقتصاد را علم ندانست؟

سال گذشته همين بحث اقتصاد علم يا شبه علم را در وبلاگي ديگر با حامد قدوسي عزيز داشتيم. در آنجا مطلبي از وبلاگ منكيو، استاد اقتصاد دانشگاه هاروارد قرار دادم كه همين سؤال را عيناً در وبلاگ خودش مطرح كرده بود. يكي از کامنت‌هاي اين مطلب كه بسيار نيز مورد توجه او قرار گرفت را مجدداً در اينجا كپي مي‌كنم و فكر مي‌كنم كاملاً استدلال منطقي در اين زمينه مطرح كرده است. از دوستان خواش مي‌كنم با دقت تمام استدلال‌هاي متن را بخوانند تا مجدداً اتهام بي‌استدلالي به ما وارد نكنند.

 

mvpy said...

Prof ManQ, I think the experimental data issue is beside the point; thats just a distraction.

I must agree with Don; economics is no science. Firstly, as Larry Summers long ago pointed out, empirical rejection of a theory in economics is never a reason to reject that theory. This hardly resonates of scientifism. Anything but. In economics, if a theory is rejected by data, that empirical rejection simply becomes a "puzzle"; frequently that data is dismissed as being "wrong". The theory itself lives on. The equity premium puzzle, for instance, casts serious doubt on conventional theories of asset pricing and, indeed, the neoclassical growth model and standard utility functions. You yourself had vehemently criticised the New Keynesian Phillips curve as being empirically invalid; yet it forms the basis of an abundance of current reaserch work. In international economics, the theories of PPP and interest parity have been faced devestating rejection in the data; again both still form the corpus of much work in this area. In a serious science, something with a lack of empirical validity would surely be quickly disavowed.

Further, theres little consensus on anything in economics. Even at the most undamental level, economists question the validity of such tenets as the slope of demand curves. Many support a higher minimum wage (Card said it would raise employment; labor demand curves slope up); many dont (labor demand curves slope down). I think if any body of knowledge aspires to scientifism, then there must be broad agreement on the very fundmentals of that discipline. In economics there isnt.

Also, and this is a very significant point. In economics you can establish a theory to prove *anything* you want. You can use data to prove *anything* you want. In this sense, any conclusion attained by an economist is necessarily suspect, since theres a lack of fundamental rigor in the first instance.