Goodhart's Law

Back in 1975 professor Charles Goodhart stated:

Goodhart's Law

Any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes

More in general Goodhart's Law is Goodhart's law is a generalized social science expression of the so called 'Lucas Critique'. Named after Robert Lucas who argues that it is naive to try to predict the effects of an (economic) change entirely on the basis of relationships observed in historical data.

Actuarial examples...
Some remarkable actuarial examples of Goodhart's Law are:

• Using coverage ratios to control pension funds
• Using z-scores to control banks or pension funds
• (Under)estimating longevity risk for decades
• Measuring (long term) rates (stocks, bonds, inflation ) for valuation purposes

Historians...
Early 2009 Goodhart proclaimed : “One of the lessons of the recent crisis, a lesson for bankers and for regulators, is, hire fewer mathematicians (actuaries) and physicists who build models on the basis of data that they can observe over relatively short period, and hire a few more historians who know what can go wrong even if they don’t necessarily have a good data basis to put into particular models”.

Although Goodhart is probably right, actuaries should keep an eye on the process....


Future developments are a function of Data, Probability, Uncertainty, Experience and above all Common Sense.

Just like the Roman God Janus, actuaries should look at the future, with the past in mind. And to do just that, we need all the help in the world, especially from historians....


Related links:
- Performance Persistence of Dutch Pension Funds (2010)

Actuarial Thought Leadership: What is success?

What is success? Are you a successful actuary?

Simple questions, easy to answer you would think. Right?

Wrong!

To illustrate the deeper  meaning and the nuance of success, let's take a look at the next 'Best Practice of Success'. A real life story from Joshua Maggid.....

'Best Practice of Success'

That day, together with my new colleague James, I entered the Pension Board's holy board room. All eight pension board members welcomed us with a hopeful smile and a firm handshake.

After introducing James as our company's brand new super professional, an unbeatable actuary and a seasoned specialist in asset liability matters, all seemed set for a successful presentation by James. Todays subject: Board decision on the new - next year's - asset allocation.

As expected, in a more than splendid and fluently short presentation, James handled everything a pension fund board member could possible think of or ask for. From headlines to all the important details. In roughly half an hour James showed his outstanding technical skills and impressed all board members. They were flabbergasted. What a knowledge, this was what one would call real Thought Leadership!

After James finishes his presentation, silence fills the board room. A kind of holy silence... Every board member is overwhelmed by James' stunning presentation. The Pension Board President quietly  looks around and breaks the profound silence as he softly says: "Thank you James.... Gentleman... (a lack of ladies in pension fund board rooms still teases us)...., is there anyone who has a question?......  (silence continues..) .  If not..... Do we all agree on James' new asset allocation proposal? (silence continues, some board members nod their head..). Does anyone disagree with James' proposal?.....(no one replies verbal or non verbal)... If not... Thank you for your continuing support. As a pension board, we've just agreed to the new asset location for next year... Congratulations!.... Dear advisory actuaries - James in particular - thank you for your effective presentation and corresponding proposal."

Aftermath

As always after I visit a client with a colleague, we meet shortly after in a nearby coffee shop to evaluate the meeting as well as each other's performance, irrespective of any form of hierarchy.

When I meet James shortly after the successful pension fund board meeting in the local Starbucks, he comes in walking with a smile....

"Peace of cake ", he opens our conversation. "What do you mean?, I ask him. "Well, making a $ 0.2 million turnover in a 30 minutes presentation, without any questions or comments, seems like a dream. I couldn't have done any better. I surpassed myself. This was one of my most successful presentations ever", James replied.

I looked him in the eye as I dropped an uneasy silence..... "This was as bad as it could get", I answered James. "How do you mean, 'Bad'? It was great, everyone agreed on my proposal, no questions at all.", James responded agitated.  

"Well - in short - It was YOU that took the decision and not the board. That's whats wrong", I stated. James again: "That's not true, I only advised, the board took the decision, not I. Let's keep things clear here, please!".

"No", I answered, "It was actually you!.... You took the actual decision. And if things in practice turn out different from your proposal (as most likely will be the case), this pension board will blame you for a wrong advice two years from now.......  

By demonstrating your enormous technical power in a half hour monologue, you've overpowered the board in such a way that they could not raise any questions or give comments without the risk of showing a form of incompetence or loss of face.

As we discussed in our preparation, you should have presented at least three different scenarios. Each scenario with a a different risk appetite. You should interactively have helped the board with choosing a well understood risk-return scenario. Asking questions, wrapping up opinions, leading the discussion to a point where the board feels that they've clearly understood what's on the table and 'feels comfortable' with the common decision taken."

James replied with anger: "When I have to do it that way, my presentations would take two hours and my preparation as well.  Above all, I have to deal with ten similar clients next week. I simply don't have the time to pick it up the way you suggest."

Moral of the story
From the above example it's clear that 'short term success' is not the same as 'long term success'.

To prevent ending up only in the reality of our own believes, constructive peer reviewing each other's performances is key to keep delivering long term top quality.

So don't forget to discuss your 'actuarial eggs' with one of your actuarial colleagues.....

Finally....
It takes 'new ethics' actuaries (and quants) to make pension fund business successful again.
Are you that actuary?

Related links:
- Making Decisions in the Pension Fund Board Room (PDF,2010)
- Investmentmentor:
   expectation, a force that will release either success or failure

Actuarial Simplicity

What is simplicity? What's the power of simplicity?

Goethe
It was Johann Wolfgang von Goethe ( listen), a German writer (poet), but also a polymath (!), who
stated:

Everything is simpler than you think 

and at the same time more complex than you imagine

And indeed Goethe was right, in (actuarial) science and  practice it's the challenge of overcoming (transcending) this paradox of simplicity and complexity.

The art of actuarial mastership
As models become more and more complex, it takes the art of actuarial mastership to condense this complexity into an outlined, understandable and (for the audience) applicable outcome.

A 'best practice example' of condensing complexity into a powerful inspiring statement, is Einseins famous equation E=MC² :

Like Paulo Coelho states in his blog about Einstein:
A man (actuary) should look for what is, and not for what he thinks should be. Any intelligent fool can make things bigger and more complex… 

It takes a touch of genius – and a lot of courage to move in the opposite direction.

Or, to quote Einstein:

Everything should be as simple as it is, but not simpler

How to cut through the actuarial cake?

Just three simple examples on how to cut through the complex actuarial cake. Examples that might help you to simplify complexity:

1. Think more simple

A perfect example of 'thinking more simple' is finding the solution of the next math problem (on the left), grabbed from an old high school math test.

Can you solve this problem within 10 seconds?

Found it? Now move your mouse over the picture or click it, to find the refreshing simple answer.....


Remember however not to oversimplify things. Sometimes problems need the eye of the actuarial master to identify important details...

2. Visual Results

Second example is to visualize the outcome of your models instead of power-point bullet conclusions or explaining how complex your model really is.

A nice example is the online dollar-bill-tracking project "Where's George?" from Research on Complex Systems, that measures the flow of dollars within the U.S. (over 11 millions bills, 3109 counties).
About 17 million passengers travel each week across long distances. However, including all means of transportation, 80% of all traffic occurs across distances less than 50 km.
One picture says it all and 'hides' the complex algorithms used, to get  stunning results.

On top of, George collects relevant data about 'human travel' that could be used for developing models of the spread of infectious diseases.

Just take look at the video presentation of George called Follow the Money to find out how to extract simple outcomes from complex models.

One of the simple results (by Brockmann) of this project is that the probability P(r) of traveling a distance (r, in km)  in a short period of time in days (max 14 days) can be expressed as a power law, i.e.:

P(r)= r ^-1.6

 3. Listen better

Every (actuarial) project outcome fails if there's no well defined goal at first.

Main problem is often, that the client isn't really capable of defining his goal (or problem) very precise and we - actuaries - start 'helping' the client.  In this 'helping' we are imposing our thoughts, beliefs and experiences onto others, by what we think 'is best' for the client. The outcome might often be an actuarial solution that fits the problem in our own actuarial head, but fails to meet the clients problem.

Main point is that we - as advisors - don't really listen well.
Of course that doesn't apply to you as an actuary personally, but it does apply to all other qualified actuaries, doesn't it?

Just to test if you're part of that small elite troop of 'well listening qualified actuaries' (WLQAs), just answer the next simple Client Problem:

Client: I'm confused about 'distances'. It turns out that measuring the distance between two points on earth is really complicated math, as the world is round and not flat.

But even in a 'flat world' I find measuring distance complicated. As an actuary, can you tell me:


What’s the shortest distance between two points in a flat world?

O.K. Now think for a moment.....

Have you got the answer to this complex client problem?

Now that you're ready with your answer, please click on the answer button to find out the one and only correct answer.

The answer is: the shortest distance between two points is zero

Hope you safely (without any mental damage) passed the above WLQA-test......

A Simple Application

A nice demonstration of actuarial simplicity is the well known 'compound interest doubling rule' that states that an investment with compound interest rate R, doubles itself in N≈72/R years.

So it'll take (p.e.) approximately N≈ 12 (=72/6) years to double your investment of $100 to $200 at an compound interest rate of 6% p.a.

While the precise equation of the doubling time is quite complex to handle, it's approximating equivalent, N≈72/R, is simple applicable and will do fine for small size compound interest rates.


It's our actuarial duty and challenge to develop simple rules of thumbs for board members we advice. We actuaries have to master the power of simplicity. Let's keep doing so!

Related links:
- The Complexity of Simplicity
- Where's George?: Wikipedia
- The scaling laws of human travel (2006)