Complexity in Monetary Policy: The Mechanisms Do Matter

Beware manufactured stability: "expectations management" is inherently fragile

A recent working paper adds to the discussion on monetary policy and growth.  In the model, monetary policy affects growth by allowing credit-intensive industries to engage in larger projects.  It does so by easing liquidity needs and, thus, giving firms the "breathing space" to invest.  The paper finds evidence for this by looking at industry-level financial constraint variables as well as the performance of the industry in response to monetary policy.  The key finding is that countercyclical monetary policy can have a significant positive impact on long run productivity growth, especially for recessions.  This result is robust to controlling for:

...the interaction between these measures of financial constraints and country-level economic variables such as inflation, financial development, and the size of government which are likely to affect the country’s ability to pursue more countercyclical macroeconomic policies (5).

Moreover, the regressions shed light on another unique internal link from monetary policy to growth: countercyclical monetary policy promotes higher levels of R+D spending.  While the model explains it through liquidity needs, the concept of "signal-processing" causing firms to invest inefficiently likely applies.  This suggests that if we really are in a "great stagnation" of growth and innovation, a stable nominal economy vis-a-vis monetary policy will be increasingly important.

To extend the model, if monetary policy exerts a diverse range of effects on what is considered money through safe asset creation, the effect of countercyclical monetary policy is probably stronger than what the interest rate would state.  By increasing liquidity through countercyclical policy, this allows firms to invest more:

The intuition for this proposition is simple. Firms need to hoard liquidity in order to weather liquidity shocks if the aggregate state is bad. This liquidity hoarding is costly...because of the lack of commitment of consumers. Reducing interest rates in bad times lowers the amount of hoarded liquidity, by increasing the ability of firms to leverage their net worth. This effect is weaker when the aggregate state is good because in that state, short-term profits are enough to cover reinvestment needs so that no liquidity needs to be hoarded to weather liquidity shocks that occur in that aggregate state of the world. Hence a higher marginal benefit of reducing interest rates in bad times relative to good times. This effect is strong enough to overcome a countervailing effect arising from the fact that lowering interest rates in bad times leads to an implicit subsidy from consumers to entrepreneurs, explaining that optimal interest rate policy is countercyclical (14, my emphasis).

And now the Nassim Nicholas Taleb homonculus starts screaming into my ear.

To what extent does this mechanism of monetary policy just create more interlocking fragilities?  I've previously argued that one of the problems with NGDP targeting is that it hides the complexity of the ecology of markets.  In this model, the world is encouraged to increase complexity because of a monetary regime that promotes more stable growth.  The firms with "unshakeable" expectations can leverage themselves to the hilt to try to maximize future growth.  But finance is fragile; what would happen if an unseen risk arises?  More seriously, although a debt crisis would wipe these firms out, nobody would be able to tell in the short run while those debt instruments are still there.

The issue here is that "average growth" is nowhere near as important as "variant growth".  While growth is stable most of the time, the impact of tail events rises as markets become more interconnected.  Leverage is inherently dangerous in an interconnected world because it enables complex cascading effects that go beyond the ability of our models to predict.  This uncertainty is heightened by the fact that even slight miscalibration errors can cause monstruous miscalculations.  These problems aren't solved by monetary policy either because financial crises are aggregate supply problems.  If credit mediation crashes, resources are no longer allocated efficiently, raising unit costs for all factors of production.

A possible way to get around this is if we can commit to more equity instead of leverage.  From Taleb's 10 principles for a Black-Swan free society:

5. Counter-balance complexity with simplicity. Complexity from globalisation and highly networked economic life needs to be countered by simplicity in financial products. The complex economy is already a form of leverage: the leverage of efficiency. Such systems survive thanks to slack and redundancy; adding debt produces wild and dangerous gyrations and leaves no room for error. Capitalism cannot avoid fads and bubbles: equity bubbles (as in 2000) have proved to be mild; debt bubbles are vicious.

This way, the net worth of companies can be converted into equity stakes, and funding can be obtained this way.  Given the outsize role of large events, this shift to a more black swan free society should occur before the adoption of monetary policies that could increase fragility.  In this world, monetary policy would allow for increased efficiency of markets while also preventing Black Swans from coming to roost.