The Inexact Science of Economics – and Brexit

Some argue that economics is not a science because it is not able to prove  theories ‘beyond doubt’ the same way as the hard sciences can. Or put another way: most economic theories cannot be disproved in the same way that Popper thought scientific theories could be disproved.

Simon Wren-Lewis objects, defining economics as an inexact science, but science nevertheless. He concedes that in economics no single experiment or regression can kill a theory but points out that economists “[…] have accumulations of evidence that confirm the applicability of some theories and reject the applicability of others. Economists’ views about what models are applicable change as this evidence accumulates.”

I find the term inexact science very fitting and basically agree with Wren-Lewis’ remarks on the topic. But then he ruins it in the last paragraph of the post:

This is why economists views about the (negative – ed) long term impact of Brexit should be treated as knowledge rather than just an opinion. Here knowledge is shorthand for the accumulation of evidence consistent with plausible theory. Sometimes the theories are common sense, like making trade more difficult will reduce trade. Estimates of the size of trade reduction based on evidence are uncertain, but they are better than estimates based on wishful thinking. Empirical gravity equations consistently show that geography still matters a lot in determining how much is traded. Finally there is clear evidence that trade is positively associated with productivity growth. To say that all this has no more worth than some politicians opinion is ultimately to degrade evidence and the science which interprets it.

Not so fast. Economists indeed know that making trade with EU countries more difficult, which Brexit undoubtedly will, will have a negative effect on British incomes. However, the EU is not only a free trade area but also (and arguably more importantly) a political union, producing a large amount of legislation each year.

For example, banking regulation is basically completely defined at the EU level, with national discretion restricted to a couple of unimportant parameters and risk-weights.

That is, Brexit will also have an effect on the laws and regulations under which the UK economy is going to operate. Will this legislative effect of Brexit be positive or negative for British incomes? As I said before, nobody can know for sure.

However, EU legislation certainly has room for improvement (to put it politely) and, in general, smaller political entities tend to be governed better than larger ones. Hence, the legislative effect on British incomes may well be positive. Furthermore, the legislative effect of Brexit might not only be positive but also strong enough to more than offset the negative effect of making trade with EU countries more difficult.

In short, the net effect of Brexit on British incomes may well be positive.

The undue certainty with which many economists have made their predictions on the economic consequences of Brexit is based on ignoring its legislative effect. This effect is, of course, more difficult to measure and to predict than the effect of restrictions to free trade with EU countries. That doesn’t mean it’s not important.

The Root of the Root of the Perverse Incentives in the Banking Sector: the Wrong Monetary Policy Regime

As I have described before, the banking sector is a mess – or as Mervyn King put it: “Of all the many ways of organising banking, the worst is the one we have today.”

At the root of the problem are explicit and implicit government guarantees for bank debt. These constitute a subsidy of debt financing and provide an incentive for banks to minimize equity to asset ratios. Razor-thin capital ratios again incentivize banks to take on excessive risk. At some point excessively risky investment behavior will produce heavy losses and lead to a solvency crisis.

Government guarantees for bank debt do not only stand at the beginning of this causal chain – they also stand in the way of a solution to the solvency crisis. Undercapitalized banks do not necessarily need to engage in credit rationing. The much simpler solution would be to issue more capital. But the taxpayer subsidy for debt has made capital artificially expensive relative to debt. Hence, banks are reluctant to issue more capital and the solvency crisis drags on.

So, if the government abolished deposit insurance (which is, of course, not insurance in the true sense of the word but simply a government guarantee) and also announced that there would be no bailing out of creditors any more in the future, would this eliminate the perverse incentives in the financial industry?

Without being accompanied by certain changes in the institutional environment (described below) such an announcement would simply not be credible and hence not effective: there are, at the moment, banks that are (potentially) “too important to fail”. Hence, the government has a strong incentive to renege on its promise and rescue such banks in the event of a crisis.

Anticipating this too-important-to-fail problem facing the government, the creditors of such banks will be content with relatively low risk-premiums. Again, the capital structure irrelevance principle will not hold and the banks will still be able to reduce their weighted average cost of capital by increasing their leverage to astronomical levels.

Without first solving the too-important-to-fail problem, the government cannot credibly commit to not bail out failed banks. But is there a solution to this problem at all?

The failure of a sufficiently large bank (or several banks) may well cause a massive negative shock to aggregate demand that cannot be offset by conventional monetary policy (i.e. by cutting the nominal safe interest rate). The economic cost associated with such an outcome (especially the cost in the form of a potentially significant rise in unemployment) may well be deemed too high to be politically acceptable.

The fact that the central bank’s power to offset negative aggregate demand shocks by cutting the safe nominal interest rate is limited (namely by the zero lower bound) is the main argument put forward to rescue failed banks with taxpayers’ money.

However, while there is obviously a limit to reductions in nominal interest rates, there is no limit to the extent to which the central bank can increase the money supply. That was Milton Friedman’s point when he complained about the failure of US monetary policy in the 1930s.

Of course, it is not enough to just increase the money supply. In order for the expansion of the money supply to increase aggregate demand, markets have to believe the increase of the money supply will be permanent. In short: the central bank has to commit to temporarily higher inflation (NGDP growth) in the future.

A fixed inflation target cuts off the Friedmanite money expansion route to boosting aggregate demand at the zero lower bound. If the central bank does not commit to deviate from its inflation target, market participants know that the central bank will collect the newly printed money again as soon as the economy is not subject to the aggregate demand shock any more. Hence, the effect of the monetary expansion on spending will be negligible.

The problem is that at the moment central banks across the world have a fixed inflation target, which means that the central bank’s power to offset negative aggregate demand shocks caused by the failure of sufficiently large banks is limited by the zero lower bound, which is again the root of the too-important-to-fail problem.

Brexit – the long run vs. the short run

There are forecasts that Brexit will precipitate a British recession or at least a significant slowdown of economic growth in the short run.

As Paul Krugman argues here and here, the assumption that the Brexit will be a major negative shock to aggregate demand does not follow from standard macroeconomic theory. Hence, according to Krugman, there is no good reason to expect a UK recession.

I agree with Paul Krugman. There is no strong reason to believe that Brexit will be a major negative shock to aggregate demand. And even if a negative shock to aggregate demand were to occur (for example, because of self-fulfilling negative expectations, i.e. firms believe there will be a recession so they reduce investment which then leads to reduced aggregate demand), monetary policy (maybe even combined with fiscal policy) could offset this negative effect by keeping nominal spending stable.

Of course, Brexit will have an effect on the British economy, namely on the long-run supply side of the economy. Krugman argues that this effect will be negative:

Brexit will almost certainly have an adverse effect on British trade; even if the UK ends up with a Norway-type agreement with the EU, the loss of guaranteed access to the EU market will affect firms’ decisions about investments, and inhibit trade flows.

This reduction in trade relative to what would otherwise happen will, in turn, make the British economy less productive and poorer than it would otherwise have been.

Ceteris paribus, i.e. given all other trade arrangements between Britain and the rest of the world and given the current regulatory framework  in the UK (which is, to a large extent, determined by the EU), Krugman is of course right.

But why would everything else stay equal?

By leaving the EU, Britain will be free to adopt a unilateral free trade policy. Many Brexiteers favour this approach and one can only hope that they will prevail.

Britain would benefit from dispensing with barriers to trade even if other countries did not do the same. It would of course be desirable if other countries also removed their barriers to trade: in this case the gains from trade would be even higher. But moving to free trade unilaterally is the optimal policy for Britain independent of whether or not trade barriers in other countries continue to exist.

Furthermore, Brexit makes it possible for Britain to embark on a new approach to, say, financial regulation. In the UK, there was virtually no government regulation of banking until 1979. Instead, the behavior of banks was subject to tight private regulation. The private regulatory framework for banking was then substituted by government regulation in the 1980s.

This approach has not been a success. Brexit gives Britain the opportunity to return to the principles that served financial markets so well before the 1980s.

Will Britain use the opportunities presented by Brexit – or will Britain’s approach to trade and regulations be more restrictive and intrusive than before?

I don’t know for sure. Nobody knows for sure.

But on the whole I am slightly optimistic. In general, smaller political entities are governed better than larger ones. And many Brexiteers have a fairly libertarian world-view.

The most important effect of Brexit may not (directly) pertain to Britain anyway but to the rest of Europe and the world. Brexit may constitute the beginning of the end of the EU, which – by imposing a large, bureaucratic, uniform governance structure on a diverse continent – is basically the opposite of competitive governance.

Let us hope that, in hindsight, Brexit indeed turns out to be the beginning of a trend towards local autonomy and governance diversity. It would be the best possible outcome.

What’s wrong with the banks?

In the 19th century banks funded themselves with 40% to 50% equity. In 2007, the US banking industry’s equity to asset ratio was 3.8 percent. For the 10 largest banks it was only 2.8 percent. What had happened?

The reason for the drastic decline in capital ratios during the 20th century is simple: since the Great Depression bank debt has been explicitly or implicitly guaranteed by the government. If creditors of a bank will be repaid regardless of the condition of the bank, they stop worrying about the condition of the bank. In particular, they will give the bank a discount on the cost of the funds it borrows and will not demand compensation for a lower capital ratio (i.e. a higher probability of bankruptcy).

In short: the government guarantee is a massive subsidy of debt financing. And minimizing equity to asset ratios maximizes the value of this subsidy to the banks’ shareholders.

The problem is that a razor-thin capital ratio creates perverse incentives for a bank’s investment decisions.

Consider the following example:

A bank is funded by 3 billion of capital and 97 billion of debt. The bank’s management can choose between two alternative strategies:

  1. Strategy A: The bank invests the 100 billion in relatively secure government and company bonds. After one period the return will be either 110 billion or 100 billion (with a probability of 50%, respectively).
  2. Strategy B: The bank invests the 100 billion in US subprime mortgages. After one period the return will be either 65 billion or 125 billion (with a probability of 50%, respectively).

In order to keep things simple, we normalize the interest rate on debt to 0%. Then the different stakeholders’ payoffs for the two possible strategies are given as follows.

Payoffs for strategy A (in billions):

creditors shareholders overall
Investment 97 3 100
return if lucky 97 13 110
return if unlucky 97 3 100
expected profit 0 5 5

Payoffs for strategy B (in billions):

creditors shareholders overall
Investment 97 3 100
return if lucky 97 28 125
return if unlucky 65 0 65
expected profit – 16 11 – 5


Note that strategy A is the efficient strategy because it maximizes the expected return from lending. However, by following an inefficiently risky business model (strategy B) the bank can increase the expected profits for its shareholders. If we assume that the bank’s management acts in the interest of the shareholders, it will choose strategy B.

In order to rein in on the perverse incentives created by deposit insurance (which is, of course, not insurance in the true sense of the word but simply a government guarantee) and other more implicit guarantees for bank debt (e.g. in the case of institutions deemed “too big too fail”) , governments around the world have been creating an ever-growing mountain of regulations.

Already before the financial crisis, the banking industry was the most heavily regulated sector in the economy. However, thousands and thousands of pages of regulations are not able to change the perverse incentives introduced by government guarantees for bank debt.

And make no mistake about it: these perverse incentives underlying the banking industry will lead to further crises.