Just Finished Reading: How to Make the World Add Up – Ten Rules for Thinking Differently About Numbers by Tim Harford (FP: 2020) [296pp] 

Numbers are everywhere. We are bombarded with them from media outlets, on the Internet and from politicians. But what, exactly, are we supposed to DO with them? When you’re told that inflation is down by 2% what exactly does that mean? When a government department has made a £5 billion deal is that a lot of money? When we’re told that migration is up by 15% since this time last year how are we supposed to react to that? 

Facts and figures thrown at us from every news programme or every tweet [side note: If tweets were part of Twitter, what do we call individual posts on ‘X’?] could simply be ignored as either lies, misinformation or just too complicated to think about (and do ‘they’ want you to feel that way about them?) but it doesn’t have to be that way. One thing you can, and the author suggests that you should, do is the pause a moment and think of how the number/statistic being presented makes you feel. Is it anger? Shock? Dismay? Elation? Or confusion? Now ask yourself: Was that emotional response the point of the figure you’ve just seen? If it is, it's time to dig deeper and start asking questions. 

Take the (made-up) figure I mentioned earlier – that migration was up by 15% since this time last year. If true (which it might not be), what does it mean? Is 15% a lot? In raw numbers does that mean hundreds, thousands or millions? If it's say, 10K what kind of percentage is that of the population? Does that number seem large to you or insignificant? So, was the 15% figure – given without context – designed to make you afraid/angry. If it was, maybe you shouldn’t trust that source about other figures. Then, of course, there’s the question of what constitutes a ‘migrant’ (a term I particularly loathe)? Does it include those studying here on 3–5-year visas who will be leaving on graduation? Does it include those who have been recruited to fill vital job vacancies in critical industries? Does it include seasonal farm labourers who will be gone in a few months? Or does it only include so-called ‘illegal immigrants’ many of which might legitimately claim refugee status?  

Once you start asking these sorts of questions several things happen – firstly you should expect to lose some of the emotional heat and then you start to LEARN things, like how things work, what figures really mean and that definitions (often unstated, sometimes on purpose) matter. After a while you stop being afraid of figures, stop being befuddled by statistics and stop being manipulated by those who suspect (rightly too often) that people tend to ‘switch off’ when they’re presented with a math problem. That, in a nutshell, is what this excellent book is all about – providing the intellectual tool-set that’s handy and easy to use when presented with facts and figures. Personally, I’m a sceptic by nature and probably always have been. This doesn’t mean I dismiss everything I see or hear. It does mean that I TEST things for logic, reason and, even sometimes, whether it makes mathematical sense. With this book I think I just got a whole lot better at the last bit. MUCH more from this author to come (I’ve already bought two of his other books). This was highly readable, fun (and often funny) and a much-needed aid for modern life. One of the highlights of the year. Highly recommended.