Bubbles, stability, Stiglitz

As soon as you guys have read the title and saw the article I’m discussing, you are probably expected me to go off about Stiglitz – given that, although he’s a genius, his views tend to be a touch unorthodox and I’m a slave to orthodox economic theory.  But this isn’t the case.  There are a couple of things I disagree with in the article, but I actually felt what he wrote was pretty good – in fact most of it is more orthodox than many may realise.

Now, I disagree with his assertion that:

They failed to predict the crisis; standard models even said bubbles couldn’t exist — markets were efficient.

Of course, the EMH suggests that we can’t predict crisis – and doesn’t say their can’t be bubbles.  Hell, the macro text book I’ve got next to me has a great deal on where bubbles pop up in models.  Personally, I’d go as far as saying that the “popping bubble” was not the main issue at stake during the GFC – it was the break down in trust and reputational capital in the finance sector combined with a slow policy response.  But I digress.

He also states:

The ultimate objective of a central bank is to stabilize the real economy, and financial and price stability both need to be seen as instruments toward this and other ultimate objectives.

This is a little loose.  The objective the central bank is to run a fiat money system without incurring undue variability in the real economy – we want the certainty and efficiency associated with fiat money and price stability, but we want to avoid ADDING to variability in real output.  My only real disagreement here is that I still believe ensuring price stability is the best way to achieve any cyclical goals from monetary policy – when he does not believe this.

But ignore this, he has some great insight, namely:

Perhaps the major failing of some of the earlier models was that, while the attempt to incorporate micro-foundations was laudable, it was important that they be the right micro-foundations.

The discipline needs to build and develop – and recognising that helps us understand that the discipline isn’t in some magical “final state” where it can provide all knowledge.  This isn’t a critique of the discipline – it is an admission that the discipline needs to keep learning and growing.  Furthemore, it shows he still believes in reductionism – which I’m glad to hear.


2 replies
  1. raf
    raf says:

    “The objective the central bank is to run a fiat money system without incurring undue variability in the real economy”….would you care to expand upon that statement?

  2. Matt Nolan
    Matt Nolan says:


    Fundamentally, all I’m saying is that they aim to try to ensure that there isn’t undue volatility on the “demand side” as far as we believe that is manageable. However, even this maximum goal of the bank does not imply no output variability – as the economy faces persistent supply shocks (relative price shocks) which the Bank needs to allow the economy to respond to itself.

    Aiming for output stability itself betrays this, and will be not only allocatively inefficient but will fundamentally reduce welfare.

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