Behavioristični makro model s smiselnimi rezultati

Na “breakthrough” članek Xavierja Gabaixa “A Behavioral New Keynesian Model” sem opozoril že julija. Zdaj je zunaj še nekoliko dodelana verzija. Gabaix je v standardnem neokeynesianskem makro modelu spremenil samo eno eno predpostavko: Lucasova racionalna pričakovanja je zamenjal s Simonovimi omejenimi pričakovanji. Torej, predpostavil je, da ljudje ne optimizirajo 30 let vnaprej, pač pa da so miopični: imajo omejene kognitivne sposobnosti in so “kratkovidni” (bolj jih zanimajo zelo bližnji dogodki kot pa denimo lastna blaginja, javni deficit in inflacija čez 30 let).

No, in ta spremenjena predpostavka bolj v skladu z dejanskim obnašanjem ljudi naredi čudež. Tudi implikacije modela nenadoma postanejo smiselne (v skladu z dejanskim dogajanjem). Gabaix na njeni osnovi pokaže, da je monetarna politika manj učinkovita od fiskalne. Da je “daljnoročno signaliziranje” (forward guidance) s strani centralnih bank zelo omejeno učinkovito in da je v času likvidnostne pasti helikopterski denar zelo učinkovit instrument spodbujanja agregatnega povpraševanja.

Spodaj je kratek povzetek članka.

This paper presents a framework for analyzing how bounded rationality affects monetary and fiscal policy. The model is a tractable and parsimonious enrichment of the widely-used New Keynesian model: with one main new parameter, which quantifies how poorly agents understand future policy and its impact. That myopia parameter in turn affects the power of monetary and fiscal policy in a microfounded general equilibrium.

A number of consequences emerge. First, fiscal stimulus or “helicopter drops of money” are powerful and, indeed, pull the economy out of the zero lower bound. More generally, the model allows for the joint analysis of optimal monetary and fiscal policy. Second, the model helps solve the “forward guidance puzzle,” the fact that in the rational model, shocks to very distant rates have a very powerful impact on today’s consumption and inflation: because the agent is de facto myopic, this effect is muted. Third, the zero lower bound is much less costly than in the traditional model. Fourth, even with passive monetary policy, equilibrium is determinate, whereas the traditional rational model generates multiple equilibria, which reduce its predictive power. Fifth, optimal policy changes qualitatively: the optimal commitment policy with rational agents demands “nominal GDP targeting”; this is not the case with behavioral firms, as the benefits of commitment are less strong with myopic firms. Sixth, the model is “neo-Fisherian” in the long run, but Keynesian in the short run: something that has proven difficult for other models to achieve: a permanent rise in the interest rate decreases inflation in the short run but increases it in the long run. The non-standard behavioral features of the model seem warranted by the empirical evidence.

Vir: Xavier Gabaix, A Behavioral New Keynesian Model

2 responses

  1. Zelo sem skeptičen glede praktične implementacije, čeprav teorija pomeni korak naprej.

    “Helicopter money” pomeni še en poskus reševanja globoke strukturne krize sodobnega kapitalističnega sveta predvsem z monetarnim instrumentarijem oz. drugače povedano: opravičilo za ohranjanje gospodarske (in posredno politične) vloge cetralnih bank.

    Boim se, da bi jedro ukrepov moralo biti drugje. Najprej politični, nato fiskalni in šele nato monetarni. V tem vrstnem redu po pomembnosti.

    Radikalno razvrednotenje denarja kar je nujna posledica Helicopeter money, praviloma pomeni razpad družb, ki se jim to dogaja, z nepredvidjivimi političnimi posledicami. Pomeni razlastitev prihrankov in če hočete, minulega dela (pokojnin) celih generacij. Najbolj ranljivi praviloma pri tem plačajo največjo ceno.

    Deflacija je realna grožnja. Ampak, če jo bomo reševali s “helicopter money” kot centralnim ukrepom, se bojim, da bomo prišli iz dežja pod kap.

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