Theory of Measure — Why I Bought a $250 Keyboard

A Mental Model for Decision Making

Callum McIntyre
4 min readJun 17, 2020

Unless you’re Jeff Bezos, you have limited resources. With the highest value resources being Time and Money.

We all need to find a decision-making process to decide what aspect of your life, or objects you acquire, require investment.

I think about this a lot, as I’m sure you do too. It can come down to any purchasing decision.

  • “What new car should I get?”
  • “How much should I spend on glasses?
  • “Should I get a new computer?”

About a year ago I heard of a mental model canned ‘Measure: a mental model for decision-making’ by Taimur Abdaal. You can find in on his Blog, and Podcast.


It essentially boils down to this.

Taimur outlines two metrics for value contribution to your life; “Magnitude” and “Measure”.

  • “Magnitude” is the amplitude of that value at a particular time.
  • “Measure” is the time over which that amplitude acts.

And I would add that value is the area under the curve.

Value = Measure x Magnitude

I have drawn to extreme examples, here.

  • One could be something like a meal out with friends, a spike in value over a short period of time.
  • The other is a purchase, something that adds value to your life every day, over a long period of time. These can be called “High-Measure” purchases.

I often think these can be things that are traditionally under-invested in. Stuff like mattresses, rucksack, good glasses, comfortable shoes etc.

I think we can agree, these are things that require investment as the make a huge difference to our lives. Never quite making our day, but adding value nonetheless.

Applicable Examples

This is something I see every-day in my job. I sell computers.

My argument is often that an investment in a laptop or computer is a very high measure thing. Take the example of a freelance creative.

They use that laptop for 7–9 hours a day, every working day, for the life of the computer (which can be as much as about 8 years). By investing in a machine that is, let’s say $2000, they not only increase the useful output-rate but also the length of the life of the machine.

Even if that machine only results in a 5% increase in your productivity, by being faster, requiring less troubleshooting and repairs over that time, you can get to a huge value-add. Let’s say you earn $10 an hour (which is a massive under-estimation, but proves a point).

Value-Add = 5% x Life in Years x Number of Working Hours in a Year x Hourly Rate

Value-Add = 5% x 5 x (48x40) x $10 = $4’800

(This is evidently a huge over-simplification but you get the point)

You might argue that you get towards the law of diminishing returns, I would agree. But spending $2000 rather than $1000 is still a significant percentage increase in speed, reliability and length of life.

What about Under-Investing?

This can also be seen in reverse if you skimp. This doesn’t happen too much, but if you go as cheap as possible, say 80% of the cost of the other machine.

You save 20%, yes, but often the cheaper is less effective over time. Or in some cases, inadequate in the first place.

Meaning you may now be spending 180% to get a machine that could have cost 100%. You could sell the other one, or pass it on to family, but there is still a loss there.

Power of Delight

You also get towards my theory of the “Power of Delight”.

I recently spent a ridiculous amount of money on a keyboard.

That keyboard has increased my typing speed, reduced ergonomic issues of thin laptop-style keyboards and allows customisation for my use.

But the biggest value-add of that purchase is the factor of delight. It’s a very nice thing.

It makes me want to type more, which makes me want to work more. Also, there is the enjoyment of the fact that I was able to build it myself.

That one $250 purchase has increased my output, reduced strain on my hands and wrists, looks nicer, will last for years and years. I would argue a keyboard is a pretty “high-measure” item.

Other Ideas

The same goes for a whole host of other things:

  • Posture
  • Relationships
  • Anything that will improve sleep

Let me know what you think. What are some high-measure items in your life?



Callum McIntyre

Growing YouTube Channels, Full Time. Content Director at Driver61 and Driven Media. But, I also like nice things - so I talk about them.