Perception versus reality : a massive statistical guide

This is a massive site comparing public perceptions to reality on a huge number of issues in many different countries. If nothing else, it provides valuable information of what issues people are misinformed about and therefore where more accurate information needs to be displayed more frequently. It also measures exactly how mistaken they are. This may go some way towards explaining why people support policies that appear to make no sense.

However, while there are a good many niche statistics that can easily be explained as a simple lack of reporting - who actually goes around knowing what fraction of prisoners are immigrants, for instance ? - there are also examples where the facts and figures are widely reported, yet people persist in disbelieving them. E.g. few people probably know the exact numerical value as to the change in homicide rates, but that doesn't really excuse this broader finding from 2017 :

Only 7% of people think the murder rate is lower in their country than it was in 2000 – but it is significantly down in most countries, and, across the countries overall, it’s down 29%.

I think the broad extent and area of the misperceptions is much more interesting that knowing exactly how wrong people are. There's an enormous number of different facts here and it would be ludicrous to either expect people to either know they off by heart or guess them reasonably accurately. That's not really the point. For example :

Most countries greatly overestimate the proportion of prisoners in their country that are immigrants, with the average guess at 28% when it’s actually only 15%. And some countries are much more wrong. For example, in the Netherlands the average guess is that 51% of prisoners are immigrants when it is actually 19%.

Who's going to know those exact values except statisticians and prison managers ? Hardly anyone. But the fact the guesses are so badly wrong, and in which direction they're wrong, tells you something about the state of reporting and rhetoric being used. It can also indicate psychological effects that cause these misconceptions. More accurate reporting would be a good start, but dry statistics are hardly persuasive rhetoric compared to emotional anecdotes. If you don't try and address the root concerns directly, the facts may really not matter.

We also suffer from what social psychologists call “emotional innumeracy” when estimating realities. This theory suggests we have two goals when answering these questions: “accuracy” goals, where we want to get the right answer, but also “directional” goals, where we’re sending a message about what’s worrying us, consciously or not.

This provides the very neat and vitally important reminder that cause and effect run both ways - our concern may lead to our misperceptions as much as our misperceptions creating our concern.

This is likely to be part of the explanation for the widespread and huge overestimates of how much the wealthiest own and what proportion of our populations are immigrants. We are worried about the concentration of wealth and immigration levels, and this is reflected in us overstating the scale of the issues.

But the survey suggests there are also some issues where we’re not as worried as we should be. For example, most countries hugely underestimate how much of their population is overweight or obese. Our misperceptions can therefore be seen as an important indicator of our levels of concern – and where we underestimate, maybe we should be worrying more (although, as we’ll come back to later, scaring people about the scale of an issue could be counter-productive in changing behaviours).

(https://www.ipsos.com/sites/default/files/2016-06/015.1_PerilsOfPerception_March2016.pdf)

Needless to say, I've not read through the entire site because it's enormous.
http://www.perils.ipsos.com/archive/index.html