Is Using Assumptions Good or Bad?

Desert island

An engineer, a physicist and an economist are shipwrecked on a desert island. All they have is a tin of baked beans but how are they to open it? The engineer considers hitting it with a rock, the physicist suggests heating it over a fire. The economist, however, smiles and says: ‘Let us assume we have a tin opener’.

I am an economist, so assumptions come very easily to me, I know how useful they can be.  However, I have also learnt to be wary of their uncritical use – and there is an awful lot of uncritical use around today. Why is this? To understand, we need to ask

What are assumptions and where do they come from?

I once assigned a problem to an engineer working for me.  I told him that he could solve the problem any way he liked, just so long as he documented all the assumptions that he made. After a couple of weeks, he supplied his solution.  “And where are your assumptions?”  I asked.  “Oh, I didn’t make any!” he replied.

I pointed to a number of the assumptions in his solution and said “What about this – and this?” “They are not assumptions” he repied indignantly, “they are the results of my years of experience!”

And that, in a nutshell, is why assumptions are so valuable – and, at the same time, so dangerous.  Our years of experience enables us to take shortcuts to get the work done but only when doing things the way we always have. When change comes, doing – and thinking – ‘the way we always have’, stops being a shortcut, and becomes a fast track to disaster.

When change comes, we need to rethink our assumptions but years of conditioning makes this very hard, if not impossible.

To succeed in a changing world, we must learn to question assumptions.

Question: But how?

2 Thoughts on “Is Using Assumptions Good or Bad?

  1. Re: the question about how we learn to question assumptions in a changing world, I think the root cause is rethinking the way we understand our role. Professionals often mistake their role as coming up with the ‘right’ answer rather than providing the information and advice decision makers need to make it themselves.

    When we start thinking this way, we learn to be draw on our “years of experience” (as per the post) but be explicit about WHY we think a particular solution is ‘right’. This may even force us to re-examine ourselves.

    The only way we’ll really be ready for change is if we have everyone on the same page, understanding / discussing / debating WHY we should take a particular course of action, rather than obeying the gospel according to the expert (with his/her often unstated assumptions). More often than not, people are unwilling to blindly accept this anyway, so bringing them on board is more likely to win the argument.

    Notice, too, that this is a language and communication challenge more than a technical one: if we fail to K.I.S.S. then we will fall at the first hurdle!

    • Penny on March 28, 2017 at 2:35 pm said:

      Brilliant! I like it. Too often as ‘experts’ we believe we are above being challenged, and even take it as an affront. But we shouldn’t. In fact, if we deliberately encourage questioning, we all benefit -because we all think!

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