Diskusija o tem, zakaj se krize dogajajo in zakaj jih ekonomski modeli ignorirajo, se intenzivno nadaljuje. Če uporabim primerjavo iz meteorologije, v bistvu imamo v ekonomiji teorijo samo za lepo vreme, nimamo pa (splošno sprejete) teorije o nevihtah ali tornadih ali dolgih ciklonskih depresijah. V neoklasični teoriji se krize načeloma ne morejo zgoditi, toda ker se vseeno pojavljajo sta Kydland in Prescott leta 1982 razvila t.i. real business cycle teorijo (RBC). RBC teorija pravi, da se realne krize lahko zgodijo, vendar ne zato, ker bi se trgi zmotili (in se ne bi “počistili”), ampak ker se eksogeno zgodijo od zunaj, denimo zaradi eksogenega tehnološkega šoka. Od znotraj se ne morejo zgoditi, saj so vendar posamezniki absolutno racionalni, trgi pa absolutno učinkoviti. To je seveda neumnost. Toda neumnost zacementirana v sodobnih ekonomskih učbenikih.

Noah Smith navaja nekaj zadnjih primerov, ko ekonomisti znotraj neoklasične tradicije iščejo možnosti, da se krize zgodijo “znotraj sistema”, in sicer bodisi zaradi nepopolne disperzije informacij med ekonomskimi agenti, kar povzroči inercijo oziroma “hrup” v sistemu (Angeletos in La’O, 2009) bodisi zaradi “mrežnih učinkov” , ko se šoki iz enega sektorja transmitirajo v druge (Acemoglu et al., 2012). Smith se na tej osnovi zadovolji z ugotovitvijo, da imajo krize najbrž vzrok v kompleksnosti sistema:

[…] if you held a gun to my head, I would say that something like this is actually going on in the actual economy. Why? Because aggregate shocks are sometimes really hard to identify. There were the oil price shocks in the 1970s and Volcker’s tightening in the early 1980s, but a lot of recessions don’t seem to be externally provoked. So maybe that means there is some kind of random mass-psychological sentiment thing going on, or maybe it means that recessions are sunspots caused by the interaction of a whole bunch of frictions, and thus completely unknowable. But this network/linkage idea seems like a promising alternative to those unhappy possibilities. That doesn’t mean I think any of these models is right – they’re all going to have empirical issues, because they are basically proof-of-concept papers. But I suspect they’re on to something that many have expected for a long time – the idea that economic fluctuations are the result of the complexity of economic systems.

To je res velik korak naprej v razmišljanju, toda to še vedno pomeni, da neoklasična dogma o popolnoma informiranih racionalnih posameznikih velja in da se kriza zgodi zgolj zaradi tega, ker se informacije nepopolno prenašajo med različnimi igralci na trgu oziroma ker se šoki prenašajo med sektorji v gospodarstvu. Toda glavni problem je prav v predpostavki popolne informiranosti in predpostavki racionalnosti obnašanja.

Ekonomija ni mehanika, pač pa zelo kompleksen in inherentno oscilativen ter nestabilen sistem. Sistem, sestavljen iz posameznikov z nepopolnimi informacijami in podvrženim čustvom, ki se na tej osnovi ter v nenehni interakciji z ostalimi nepopolno informiranimi in čustvenimi posamezniki hipno odločajo. Vsaka njihova odločitev vsebuje določeno mero “hrupa”, kar dela sistem inherentno oscilativen, in vsaka odločitev lahko drastično obrne tok dogajanja.

Dober način razumevanja ekonomije je zapis kompleksnosti in inherentne oscilativnosti gospodarstva, ki ga je pod Smithov članek v komentarju objavil Absalon:

Rhetorical question: could an economy consisting of ten actors who are in constant, open communication with each other, and who have the ability to co-ordinate, suffer a recession?

If one created a model using linear first order differential equations with a thousand or so actors, ten or so variables to describe each actors investments, liabilities and conduct and some variables to describe the actor’s beliefs (with the beliefs constantly relaxing towards the current true state of affairs as information diffuses) the resulting model would look like:

y’ = Ay + small noise factor.

If you have one thousand actors and twenty thousand variables then A will have twenty thousand, mostly complex, eigenvalues and the system will inherently oscillate in a very complex fashion as a result of the combined effect of about twenty thousand separate frequencies. External shocks are not needed to make the system oscillate. Now assume you have twenty thousand actors.