Ne boste verjeli, toda v (makro)ekonomiji je ena izmed ključnih predpostavk ali so plače in cene navzdol rigidne ali ne, torej ali so “lepljive” (“sticky“) ali ne. Jasno, da so rigidne navzdol, v času krize se podjetja (če že ne zaradi drugega, pa zaradi pritiska sindikatov) običajno prilagodijo bolj prek odpuščanja kot pa prek zniževanja plač. Toda ta predpostavka lepljivih plač v makro modelih običajno ne nastopa.

Vendar je ključna. Prvič, ker vpliva na to, kako pravilno oceniti strukturno brezposelnost, to pa vpliva na izračun potencialnega outputa ter seveda na izračun “dovoljenega” strukturnega deficita, kot ga predpisuje fiskalni pakt EU (o tem bom več pisal ta petek v Financah). In drugič, ker vpliva na naša predvidevanja ali bo kriza delovala kot nominalni ali realni šok, to pa vpliva na to ali bodo plače (in cene) delovale kot absorber šoka, kar pa seveda spet determinira izbiro ustrezne makroekonomske politike.

Ta debata je spet močno oživela v zadnjih tednih. Spodaj je nekaj zadnjih komentarjev na to temo.

Simon Wren-Lewis v Nominal wage rigidity in macro: an example of methodological failure piše, da se makroekonomski modeli otepajo lepljivih plač, ker je tujek v maksimizacijskem obnašanju racionalnih subjektov (ker ni “mikro fundirana”):

My first complaint is that too many economists follow what I call the microfoundations purist position: if it cannot be microfounded, it should not be in your model. Perhaps a better way of putting it is that they only model what they can microfound, not what they see.

… A good and very important example comes from the reluctance of firms to cut nominal wages. There is overwhelming empirical evidence for this phenomenon (see for example here (HT Timothy Taylor) or the work of Jennifer Smith at Warwick).

…

Yet debates among macroeconomists about whether and why wages are sticky go on. As this excellent example (I’ve been wanting to link to it for some time, just because of its quality) shows, they are not just debates between Keynesians and anti-Keynesians, so I do not think you can put this all down to some kind of ideological divide. I suspect nearly all economists are naturally reluctant to embrace cases where agents appear to miss opportunities for Pareto improvement – I give another example related to wage setting here. However in most other areas of the discipline overwhelming evidence is now able to trump these suspicions. But not, it seems, in macro.

While we can debate why this is at the level of general methodology, the importance of this particular example to current policy is huge. Many have argued that the failure of inflation to fall further in the recession is evidence that the output gap is not that large. As Paul Krugman in particular has repeatedly suggested, the reluctance of workers or firms to cut nominal wages may mean that inflation could be much more sticky at very low levels, so the current behaviour of inflation is not inconsistent with a large output gap. Work by the IMF supports this idea. Yet this is hardly a new discovery, so why is macro having to rediscover these basic empirical truths?

…

How could the Commission have been so foolish as to believe the natural rate had risen from 10% to 27% in a few years? Might it be because they looked at nominal wages in Spain, and inferred from the fact that nominal wages were not falling that therefore actual unemployment must be close to its natural rate? If empirical macromodels as a matter of course allowed for the absence of nominal wage cuts, would they have made such an obvious (to anyone who is not a macroeconomist) mistake?

Paul Krugman v Sticky Wages and the Macro Wars govori o tem, kako so predpostavko lepljivih plač v “vojni” med makroekonomisti v 1970-ih izgnali iz makro modelov:

You see, the question of wage (and price) stickiness, and hence of real effects of changes in nominal demand, was what the great rejection of Keynesianism was all about. And I mean all about. Back in the 70s, there was hardly any discussion of the determinants of nominal demand; what Lucas and his followers were arguing was that Keynesianism must be rejected because it was unable to derive wage stickiness from maximizing behavior.

Lucas initially argued that unexpected nominal shocks still mattered, because people couldn’t initially distinguish them from real shocks, but that this offered no room for useful policy. Later, freshwater economics rejected even that proposition; the business cycle was all about real shocks, with demand playing no role at all.

At no point was this rejection of Keynesianism driven by superior empirical performance; it was all about the principle, about refusing to incorporate anything that wasn’t derived from maximization all the way.

V Wage Flexibility in Doctrine and Policy pa Krugman govori o negativnih efektih fleksibilnosti plač navzdol v stanju ničelnih obrestnih mer:

I probably should have made clear in my post on sticky wages that I was arguing for stickiness as a central issue in the history of macroeconomic thought, not as a central issue in current policy. I’ve been arguing for years that when you’re in a liquidity trap wage flexibility actually hurts rather than helps; this is the paradox of flexibility, which arises, roughly speaking, because under current conditions the aggregate demand curve is upward-sloping thanks to debt and balance sheet effects.

But if we look at the way the civil war emerged in macro during the 1970s, both sides assumed downward-sloping aggregate demand (the liquidity trap was a distant memory), so the whole focus was on aggregate supply. The key issue then because whether it was acceptable to assume an upward-sloping short-run AS curve even though we had no “microfoundations” for that assumption, just observation of reality. Half the relevant profession decided that although it might be true in practice, it wasn’t true in theory, and therefore couldn’t happen.