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The McNamara fallacy: Measurement is not understanding

mcnamarafallacy.com

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Re: The McNamara fallacy: Measurement is not understanding

#21
post #2

From a game-theory POV, all wars are caused by misunderstandings / partial information. If each side really knew the true strength of the other side, it would be clear which would win and therefore actual war is illogical and unnecessary.

This seems untrue.

There are also genuine uncertainties about the future: things that neither side knows but will impact the outcome. Because of that, there is always a range of outcomes for a conflict, and so both sides would still have an incentive to carry out the war.

Consider, for instance, if there are two countries (A and B) looking at conflict with perfect information. Given their relative strengths, the war will cost both $1 billion, but A will win and reap $1 billion + $1 in plunder. In your model, B will always surrender and give A $1, but the reality is there is a big spread about both the costs and the gains. Lots depends on how well each side fights and responds, even with perfect knowledge of the other.

So...you know, if it's the US versus...the Philippines[1], then sure, the uncertain range of outcomes is small enough that rational thing for the Philippines to do is surrender. But for countries that are even reasonably well-matched, they would want to fight with the goal of making the conflict unattractive for the other side. Probably the best historical example of this is the USSR in Afghanistan.

[1] I am sure the US would never invade and occupy them just because the US found it convenient ;)

Re: The McNamara fallacy: Measurement is not understanding

#23
Quick story: I was the CFO for a company that sold to a private equity group (PEG). I took over as the CEO as the founders retired, leaving me to deal with the PEG. It quickly became apparent that the PEG managers looked at everything through the lens of an Excel spreadsheet. These guys were brilliant attorneys and analysts but lacked experience building businesses and managing teams. Ultimately, they couldn’t add much value in terms of operations or strategy, but they were great at financial modeling/quantitative analysis and forcing us to justify expenses. That may sound good at first—eliminating wasteful spending—but it ultimately led to the gradual erosion of the company culture and employee loyalty. It’s easy to cut benefits and pay given that many workers lack the leverage to do anything about it, while it’s much harder to reduce hard costs like materials and equipment. That meant employees just kept getting squeezed, and it was surprisingly difficult to quantify the impact that terminating an employee or cutting benefits would have on morale/culture/performance.

The moral of the story is that people with analyst mindsets play an essential role in our economy, but sometimes giving those people power over large organizations can have disastrous consequences. There truly is a disconnect between measurement and understanding.

Re: The McNamara fallacy: Measurement is not understanding

#24
post #14

Earlier quoted context omitted.

> If each side really knew the true strength of the other side, it would be clear which would win This is too simplistic. Often wars are heavily influenced by things other than just the strengths of both sides. For example - What if the ground hadn't been soaked from days of rain at Agincourt and Waterloo? What if the Germans hadn't held back their armor reinforcements for so long on D-Day?

They'd still lose. Wars are fought not from individual battles but from logistics. Modern military's don't even engage if there isn't a lopsided power imbalance favoring their success.

Yeah like in Black Hawk Down.

Re: The McNamara fallacy: Measurement is not understanding

#25
> What McNamara didn’t keep track of was the narrative of the war, the meaning that it had both within the military forces of each side, but also in the civilian populations of the nations involved.

I'm probably not following and not saying it's easy but aren't there some metrics you could track that with? How was it determined/measured later that the meaning was important? Couldn't you at least do polls in your own country?

Re: The McNamara fallacy: Measurement is not understanding

#26
post #12

I don't understands what the fallacy is. It is that an overreliance on data can overlook factors not in the data? Why is that a surprise. You would also have to show that not relying on data would generate better results.

It's probably one of those things that might seem more obvious in simple cases, but might surprise folks in more complex cases. For example, a simple case: Say you go on vacation for a few weeks with a certain amount of cash to spend. Upon arriving at your destination, you immediately purchase some indulgence, and, hey, you're feeling better! Why not immediately keep spending as much as possible to maximize? For exam…

GDP is actually a great example. It's actually very easy to increase a country's GDP if that's the only thing you care about. You just borrow more money and then spend it. GDP is literally a measure of money changing hands inside a country. If you borrow as much money as you can and then spend it on things like infrastructure projects, you can instantly increase the GDP. Banks see the growing GDP figure and assume that its a good thing and let you borrow more money. That is, until they don't.

This happened with Brazil in the 1970's, when the oil crisis made Brazil believe that they were going to face a downturn. To overcome this, they borrowed money and went on an infrastructure spending spree. This made Brazil look like an economic miracle, growing when everyone else was struggling. This encouraged more banks to lend to Brazil. The problem is the money was spent on short term growth instead of things that would more systematically grow the economy over the long term. The government (and lending banks) was substituting year-to-year GDP numbers for economic health. Once credit tightened in the early 1980's, Brazil's growth plummeted.

This is of course an over simplification, but I think we are seeing similar problems in modern economies. People often cite China's GDP growth, but they don't balance that out with the debt they are taking on in order to finance that growth.

Re: The McNamara fallacy: Measurement is not understanding

#27

I don't understands what the fallacy is. It is that an overreliance on data can overlook factors not in the data? Why is that a surprise. You would also have to show that not relying on data would generate better results.

There are a bunch of factors and implications from the piece, which I had hoped they'd go into. But some of the more obvious implications which are often more organizational than they have to do with the data per se:

- the data you are collecting may not include factors that are consequential to outcomes. Treating these unmeasured factors as inconsequential is hazardous. The piece specifically mentions this effect. This effect is not a surprise but yet many organizations fall into this trap so it seems to be worth mentioning.

- the difficulty of measuring some factors will result in their exclusion from the dataset. Some things are intrinsically hard to measure, and many organizations will as a result refuse to measure them, and make decisions without them. There needs to be a conscious and active process organizationally to resist this and find effective ways of measuring them.

- the difficulty of measuring some factors will result in easier but less useful proxies being used in their place. Same as above just with a somewhat different outcome. Organizations are often blind to this happening as they come to believe the proxy is as good as the real measure (or sometimes even that the proxy is the measure). A good industry example of this is clickthrough rates being treated synonymously with audience interest or content quality.

And a point I wish the piece made but did not:

- measuring something does not grant automatic understanding of the phenomenon and gives you no predictive power. It's one thing to quantifiably know the blue button gets more clicks than the green button, but that grants you no insight into why. Many tech companies fall into this trap - where despite investing heavily in experimentation their modeling of the product space doesn't improve over time, since they fail to take the step to convert observation to generalizable hypotheses that improve their model for the product and market.

This last effect IMO is huge in our industry, and is why the same low-level experiments are being re-done over and over again. This creates more product churn and reduces your product velocity - since the lack of proven product models means you're mostly flying blind and using ex-post-facto experimentation on live users to figure out what to do.

Experimenting on button colors is all well and good, but the end result of that data should be a color theory that explains what colors to use when, not forever A/B testing every single button color for the rest of time.

Re: The McNamara fallacy: Measurement is not understanding

#28

This article is good, but not great - the author only gives one example of how quantitative-only reasoning can be bad (the example of the poppies). The other "example" is just the US military lying. There are also no specific examples of non-quantitative reasoning that, if ignored, would be damaging. I feel like the Wikipedia article does a better job explaining this: https://en.wikipedia.org/wiki/McNamara_fallacy Al…

The example with the US military lying certainly demonstrates another issue with over valuing metrics - making sure you have good data. People who get wrapped around metrics also tend to not look at the data they are being presented. One of the issues McNamara had was he was receiving inflated body count figures. [0] Not only was he measuring the wrong thing, he was measuring it badly.

[0] https://en.wikipedia.org/wiki/Vietnam_War_body_count_controv...

Re: The McNamara fallacy: Measurement is not understanding

#29

> What McNamara didn’t keep track of was the narrative of the war, the meaning that it had both within the military forces of each side, but also in the civilian populations of the nations involved. I'm probably not following and not saying it's easy but aren't there some metrics you could track that with? How was it determined/measured later that the meaning was important? Couldn't you at least do polls in your own…

But that’s the point - it’s not just how many, but what they are willing and able to do, their positional and operational strengths and weaknesses, and so on. Condensing all that into a number is impossible.
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