June 2017 – Page 2 – Applied Macro

Money 3 Banking – a money creation myth

I will again use the bestselling undergraduate textbook “Macroeconomics” by Greg Mankiw as the source for this story.

How does money get created?

In the beginning, there were bank reserves……

The Central Bank determine Bank Reserves – this is the money that the banks have on deposit with the Central Bank
Banks, holding these reserves, then lend them out to customers, who then either put that money on deposit themselves or transfer the money to someone else who does. The mountain of customer deposits is generally many times larger than bank reserves. This is known as the “reserve-deposit ratio, rr”.
It is an “exogenous variable” in other words “the model takes as given”.
There is also the currency in circulation which the central bank also determines.
This is known as the “currency-deposit ratio, cr”. It is also an “exogenous variable”.
Combining these via “money multiplier”, gives you the Money Supply.

In this way, the Central Bank determines the level of reserves, and thus controls the money supply in a predictable way.

From bank reserves to money supply to inflation……

The next stage in this story is the “Quantity Theory of Money” which “remains the leading explanation for how money affects the economy in the long run.”
This starts with a key identity or equation:

Add a few assumptions….

P * Y is also nominal GDP, so if we assume that V (the income velocity of money) is constant (or “exogenous”), then a change in M leads to a change in nominal GDP.

Via a separate assumption, the level of output Y is determined by a production function which does not include money, therefore a change in M leads to a change in P i.e. changing the money supply causes inflation.

Economists are taught this key conclusion at university:
“Thus, … the central bank, which controls the money supply, has ultimate control over the rate of inflation.”

Unfortunately, like many Creation Myths none of this is true.
As Mankiw says, this model “is simplified. That is not necessarily a problem.”
I agree, “all models are simplified”. But when causation is the wrong way around, this is a massive problem.

Banking – a personal perspective

When I left university, I became a trader at a bank, spending many years on a money markets desk. It is at the least glamorous end of trading, but I found it fascinating being at the centre of the banking system, funding the bank’s activities, and forming the link between the Central Bank and the markets. What was immediately striking was that bank operations were nothing like the models I had been taught at university.

In the story above, the driving force is the Central Bank adding reserves, causing banks to lend money. The mechanisms described are correct, just in the exact opposite order. The actual sequence goes something like this:

Customer decides to buy something and uses credit card for the purchase.
Transaction goes through. i.e. bank lends the customer money for the purchase.
The money shows up as a credit entry on the shop’s bank account and a debit entry on the credit card.
The banking system now has a debit and a credit. Banks move the money between them to square their accounts.
It is important to note that the central bank wasn’t required to do anything in this process.

What if the customer takes out cash? Then the banking system is short of reserves.
This is not a problem as the central bank just adds or takes out reserves on a regular basis to make sure the banking system has exactly as much as it demands.

It is not the case that the Central Bank tells the bank funding desk it has more reserves, who then calls round the rest of the bank to tell them to do some more lending. In simple terms the central bank sets the rate of interest (Fed Funds in the US and the Base Rate in the UK) and then supplies money as demanded. The supply of money is determined completely by the demand for money.

Evidence

Correlation of money supply with inflation

Milton Friedman and Anna Schwartz “wrote two treatises on monetary history that documented the sources and effects of changes in the quantity of money over the past century.” What they did was document that money supply and inflation are positively correlated. This is a most obvious prediction from either story of money, and so I have never seen an argument that it supports one over the other. As inflation rises, then more money will be demanded in the economy to facilitate transactions. The central bank accommodates this so we see a direct relationship between money and inflation. This tells us nothing about causation. Friedman’s attempts to show causation by econometric tricks with “long and variable lags” are completely bogus.

Stability of velocity of money

An argument for why one can assume V is a constant, is that historically, over short periods, it has been. Unfortunately, this again is a direct prediction from both stories. If the central bank always supplies as much money as is demanded then there is no reason for velocity to change.

Why did QE not lead to hyperinflation?

According to this monetary theory in the textbooks, the vast increase in reserves caused by Quantitative Easing should have led to an explosion in bank lending and a rapid rise in inflation.

This clearly hasn’t been the case, and in fact, the taught theories really struggle with reality here. They are forced to rely on ad hoc and non-quantitative explanations such as “animal spirits” or a reduction in confidence. Since this “confidence” is not directly predictable or even observable, it requires a leap of faith, equivalent to “magic”.

It’s a wonderful coincidence that a model which predicts a MASSIVE stimulus finds, in reality, an unseen counterbalancing force which is of EXACTLY the same magnitude. But still, I read that MV=PY holds and the miraculous drop in V to exactly offset the rise in M, was a bizarre coincidence and that once the velocity of money rises back to “normal”, inflation will come.

There is a much simpler explanation. The amount of loans created by banks was never constrained by reserves and so increasing reserves has no effect on the behaviour of banks or their clients.

What do central bankers say they are doing?

Central bankers involved in monetary policy and the oversight of the banking system must understand how banking works. What do they say is going on?
They agree with my model and say that “the reality of how money is created today differs from the description found in some economics textbooks” and describe the model that is taught as “some popular misconceptions”. http://www.bankofengland.co.uk/publications/Documents/quarterlybulletin/2014/qb14q1prereleasemoneycreation.pdf

Conclusion

Money is simply not exogenous and does not cause inflation.

Amongst practitioners, including bankers and central bankers, this is obviously well understood. Bagehot famously described it perfectly in 1873. What is striking is the contrast to academic economists who persist with a very different mythical version of banking and continue to educate our bright, young minds with a story of pure fantasy. So why do they do it? I will speculate on that in the next post.

Feedback

As a member of many teams over the years, both leading and contributing, I have learned a lot about feedback. How it is dealt with is a core aspect, not only of work culture, but also in all our relationships. In this post, I will deal with the kind of feedback which is meant to have a purpose, that of improving performance, often thought of as coaching.

Coaching is at its most useful when it is an active exchange of mutual learning. On the one hand, I find I learn so much trying to explain concepts to others, whilst on the other hand I very much enjoy the experience of being coached myself. Effective coaching is rarely dominated by telling people what to do.

Encouraging self-reflection and evaluation within a context of mutual respect and desire for improvement are critical to achieve progress. You cannot presume that someone wants a coaching relationship with you, and they may perceive attempts to coach them as unwarranted criticism.

I think it is helpful to break feedback down into 3 types: praise, encouragement of self-reflection and evaluation, which can be either objective or subjective. It is also important to make a distinction based upon the type of relationships or power dynamics involved.

This leads to a grid, similar to the one used in “How to Write”.

Type 1 – Praise

Very often when people say they want feedback, they only want praise and it quickly becomes a vacuous form of feedback. We have all heard the disparaging stories of “millennials” who are conditioned to expect it. Indeed, I have come across this problem with juniors but I feel anyone adjusting to the world of work, especially straight from university, may find the real-world environment a challenge. I probably did myself.

People who have had a career in a more protected environment, or who have low self-esteem, may also need frequent reassurance that their work is valuable. We see that praise is the only form of feedback that Donald Trump can tolerate. Whereas seasoned and successful professionals tend not to seek praise as much. They know that when validation of their work comes, it is well deserved but their self-esteem is strong enough not to require it.

Like most people I enjoy being praised, but If I am highly praised for something I do not consider particularly worthy, then it has very little meaning to me. My greater desire is to learn and improve, so I actively seek other types of feedback. However, I do believe that praise is underrated as a feedback tool and it can be a very effective form of teaching, positively reinforcing good behaviours if used selectively. This is the way that I like to use it and to receive it.

As parents, praise is totally natural, we proudly clap our children at the slightest provocation. Children are naturally experimenting with behaviours and desperate to learn through new experiences, so selective reinforcement is very powerful. Genuine strong praise for a child who has tried hard at something is mutually rewarding and comes very naturally.

Overall, my approach is to try to use praise genuinely, but it is not as easy as it sounds. At work, I often start with praise but mix in other forms of feedback. This often carries the risk that the recipient may not hear the praise at all, and in fact perceive the whole conversation as pure negative criticism, especially given our power relationship. Furthermore, where the need for praise is too strong, then validation becomes an obstacle to learning in itself. If they receive a lot of praise, then why change behaviour?

A general principle is that people tend to give out the type of feedback they like to receive themselves. If I am managing a person who only wants praise, I struggle to manage them and these relationships have not worked for either of us

Type 2 Encourage self-evaluation

This is simply asking someone their thoughts on what they did or how they feel something went.
This is a type of feedback that may not register as feedback to many people, it does not involve any praise or criticism, no evaluation or active coaching.
The idea is to encourage reflection and to start a conversation from which you both can learn.

This style of feedback comes naturally to me and is most enjoyable if the other person wants to participate. Receiving this type of feedback from investors, it led to the most enjoyable and engaging conversations and I think I learned the most.

Remember the most common source of this form of feedback is yourself!

Type 3a Evaluation – Objective

This is a very important type of feedback if you can get it.

In modern sport, virtually every facet of the game is reduced to statistics which can be measured and help form the development of training drills to enable a player to improve. Purposeful practice requires a solid feedback mechanism.

Learning without a reliable feedback mechanism makes objective evaluation much harder. Learning to trade for example. A market making environment lends itself to objective evaluation as the number of transactions is likely to be high and the speed and accuracy of pricing can be easily observed. But it is one of the reasons that learning to trade by taking risk in markets is difficult, as in the short term the element of luck is large enough to create noise in the consequences of your decisions.

If evaluation is clearly objective and applied transparently to all staff, then it is likely to be accepted. But the attractions of this type of feedback are also its drawback. It is appealing to generate objectives which are measurable, but not necessarily relevant to the goals of the organisation. Think of the Blairite obsession with targets in health and education, which created distortions in incentives.

Type 3b Evaluation – Subjective

Subjective evaluation is the most overused form of feedback, and most people seem to think this is what feedback is. If you look at the forms that HR demand you fill out for conversations with your staff, you will see the word evaluation everywhere. This is often combined with a requirement to assign scores or rankings to various aspects of the employee, creating the illusion of objectivity but they are actually the opinions of the manager.

Subjective evaluation may have a place. If your intent is to make a complaint then this can take the form of a negative evaluation, for example if you want to complain to a hotel you can give a low rating on TripAdvisor. But there is wide variation in the quality of such comments. In large firms however, negative evaluations are used almost exclusively as part of the process of firing employees.

When I ran a large fund, I had hundreds of investors, old and new, continually evaluating me. If I agreed with the evaluation, it was likely it became an experience of being berated rather than a learning point. If I did not agree with the criticism, I still had to take it.

In close work environments, the giving and receiving of such feedback can be a minefield. It can be hard to receive emotionally, especially when the receiver doesn’t accept the view or worse the right or competence of the person to evaluate them. Unsolicited feedback is pure criticism – no one likes to be criticised. This is why, in practice, most work evaluations turn into exercises of giving praise, even when it is not genuinely deserved.

The relationship matters

What is striking about the workplace is how little useful feedback is given and/or taken.

If you are the in a position of authority, care must be taken not to blindly hand out feedback that could be construed as pure criticism. Remember anything you say has a magnified impact, given the nature of your relationship. Consider layering in the various forms of feedback I mention, remember the idea is to help your employee, not to add unnecessary strain or distance.

If an employee receives feedback that they don’t like, it can often be seen as confrontational or rude, and instead of trying to work out what was the purpose of such feedback the employee is more likely to grumble about them behind their back. A very poor outcome for both parties.

If you are a person who wants to improve, you need to actively seek out feedback from people you respect, this is key to improving performance. Avoiding criticism is an ingrained social habit, so bear in mind you need to be prepared for an honest evaluation. Keeping any defensive reaction in check is important as if you react defensively, you are likely not to hear honest feedback again. You should thank the person for the feedback and do your best to understand it. If you think it is completely wrong, then you still have an important learning point, that someone you respect perceives it to be true.

Conclusion

How to manage feedback is one of the most important aspects of work culture and defines whether your organisation is going to merely stagnate or rather learn and develop.

As a giver of feedback, it is important to recognise what kind of feedback the person wants and will be able to process.

As the receiver of feedback, you have the main power. You can be defensive and only accept praise, or you can actively solicit opinions which you can incorporate into your learning process.

Money 2 – an alternative history

In the beginning, there were people….
People have social interactions which have very strong patterns. One of these patterns is the concept of Reciprocity. If someone gives you something you have a strong sense of obligation to give them something back. This forms the basis on many successful marketing strategies (see “Influence” by Robert Cialdini) but also sits at the heart of everyday social interactions.

For example, in the office someone makes coffee for you. This creates an implicit obligation which you will wish to later reciprocate, or perhaps “repay”. In fact, the word “pay” is said to come from Latin “pacare” meaning “to pacify” and later came to mean to settle a debt. You do not immediately barter, need to give something in return at that time. You have a social relationship and there is mutual trust that this obligation will be repaid. This obligation could be called a “debt” or a “liability”. The person who made the coffee now can be seen to be holding an “asset”.

Make it more useful by adding features….
This method of economic organisation works well for small items between tight-knit or homogenous groups. But it would be far more powerful if we could add some other features which allow us to expand it:

Unit of measurement.
It is handy to be able to quantify the economic value of the transaction so that more complex exchanges can be facilitated
A method of recording ledger items.
Just remembering that it is your turn to buy doughnuts for office is not sustainable for more complex economic transactions.
Tradability to a 3rd party
It would be great to be able to have the favour repaid by someone other than the recipient.

A voucher system….
So let’s start a voucher system. Every time you do me a favour such as babysit my kids I will give you a voucher. Every time I do a favour such as mow someone’s lawn I will be given a voucher. I can build up a stack of voucher from doing these jobs and then “spend” them by taking my family to a restaurant for dinner.

This system of money can be seen today in small areas. In the UK, there is the Lewes pound and the Brixton pound. Tight-knit communities can develop all sorts of formal and informal social conventions to regulate exchange. None of them require gold. These are the sorts of systems of money found in ancient, primitive societies. There is no strong archaeological evidence because this kind of money is not physical, however the earliest writing ever discovered was on tablets thought to represent ledger type records. Tokens in the form of Coins are in fact a later discovery and this has commonly been misunderstood as thinking that it was the tokens themselves that were the valuable item. In fact, it was and is the social obligation that matters, coins were simply a means of recording it.

Using a central authority to widen the usage….
But these local currencies or voucher systems have limitations. They rely on trust which is hard to foster with strangers. It would be much more powerful to have some authority or government to issue the money and guarantee its use across a broader area. This is when we see minted coins by a sovereign.

The unit of value can be solidified by collecting taxes in that unit. You will notice that you owe your taxes in US dollars in the US, and in pounds sterling in the UK. The benefit to society is huge, economic activity can be distributed and exchange facilitated on a grand scale. There is also a large benefit to the government, as issuer they get to earn seignorage.

Conclusion

The alternative story of money is still taught, but these days it is mainly in sociology, history or anthropology departments. This version has been eradicated from economics faculties and treated as “fake news”. Economics students are not taught arguments to support their story, it is simply assumed and most are even unaware there are other ideas.

First Order Approximation

I used this phrase in a post two weeks ago (Models – How do computers play chess?), and in causing some debate, has made me realise how it has both subtle and important differences in meanings. This has implications for how we approach problems and links to some of the root causes of mutual incomprehension that I often come across.

Some of the different meanings:

1). General usage
It is the same as “first approximation” or a “ball park estimate” and used interchangeably. It is an educated guess with a few assumptions and likely a simple model. I think this is the most common usage. It tells you nothing about the nature of the model as this will vary by context.

2). Engineering/physics
Often used as an indication of level of accuracy, like significant figures, and this accuracy improves with higher orders of approximation. For example, if estimating the number of residents of a town the answers could be:

1st order approximation / 1 sf 40,000
2nd order approximation / 2s.f. 37,000
etc.

3). Mathematics
1st order often refers to linearity. For example, a Taylor series of a function of the form:

1st order approximation a + bx (also called a linear approximation)

2nd order approximation a + bx + cx^2 (also called quadratic)

Order also exists in statistics, with arithmetic mean and variance known as the first and second order statistics of a sample. Skew and kurtosis are third and fourth order and can be thought of as shape parameters telling how far from the normal distribution you are.

4). Financial derivatives pricing
For option pricing, it refers to the order of differentiation, so is helpful when thinking about sensitivities in the change in price:

1st order approximation Delta (1st derivative of price with respect to underling price) 2nd order approximation Gamma (2nd derivative of price)

For bond pricing, second order approximation is also called convexity adjustment which again is used to help understand the non-linearity of bond prices.

5). It can refer to the number and importance of the variables in a model.

A first order approximation may only deal with primary drivers. A second order model would include secondary drivers used to refine the estimate.

For example, a first order approximation of the time taken for a ball to drop would be to use Newton’s second law, F= ma. A second order approximation might include some appreciation of wind resistance.

The meanings may not align

These definitions might appear to be much the same thing. You can easily argue that a simple linear model using only the most important drivers will produce a decent ball-park estimate to one significant figure.

But this apparent similarity of definition means that a common trap is to not notice when they are different.

A first order approximation can be quadratic

To estimate the height of a cannon ball after firing we need to draw a parabola not a straight line. Often the non-linearity is so important that any linear model is awful.

(see How Not to be Wrong: The hidden Maths of Everyday Life by Jordan Ellenberg).

Making estimates more “accurate”, using higher power terms may make the model worse
In maths or physics textbooks, this approach always works out given that you already know the mathematical function or have an underlying relative which is stable. But in the world of economics and finance it can lead to a huge methodological error, thinking that the better our model fits the data the better the model. I worked with many analysts who have struggled with this and kept producing models with wonderful correlations and R^2. This leads them to think they have a model which “explains” the price action as well as possible. But these models are invariably useless, have no predictive value and need to be “recalibrated” to make them refit new data as it comes in.

It takes judgement to know which variables to use.
For instance, in the example with dropping an object, Newton’s second law will do an excellent job on a ball bearing from 10m but a pretty poor job on a parachutist. Which drivers will be important in financial markets varies over time and it takes a lot of flexibility to stay open-minded as to potential outcomes.