[semi-extrinsic]

Trying to look up statistics on this, and what I find is very strange:

Both in Europe and in the US, average age of vehicles on the road is given as ~ 11 years, while average age at scrappage is given as ~ 15 years.

How do you even make an age distribution that agrees with those numbers? How do you make those numbers agree with the statistics of vehicles sold per year, which is relatively steady?

[Zenst]

A few ways when you use averages and only use one type of average - mean average without including mode or median average types.

The age of on the road vehicles can be skewed by new cars. The age of scrappage can equally be skewed by a few new cars written off and as such, scrapped. Then we do not know average time of the road, the transition time of sitting in a garage/off-road and then scrapped a few years later. That could be a short period or decades. That again would skew averages.

As you can see - I have a pet hate about averages when they just use the mean average. Without knowing the other two averages or complete access to the data-sets - a biased perspective can and will be the outcome more often than not.

It's like a company employing 100 people - 99 earn 10k a year and one earns 1 million a year. The company can and often will say that their employees earn on average 19.9k a year. When the median and mode forms of averages would both in this instance yield an answer of 10k.

I'd be most happy if any use of averages has to include all 3 forms of averages - after all, we do teach them in school's, let's use them and save so much confusion, bias and statistical abuse.

https://en.wikipedia.org/wiki/Average

[billforsternz]

I like your thinking. I've always thought mean, median and mode should be thought of as different possible "average" definitions. But common usage always seems to have average == mean, and the other two as slightly less important ideas. This Wikipedia article pleasingly implies my (and your) preferred model is actually the correct one.

[Someone]

The number of cars is growing (https://www.statista.com/statistics/183505/number-of-vehicle...)

If it grows faster than sales, fewer cars must be taken of the road.

Could be as simple as households holding on to cars longer because they cannot afford to replace them, because modern cars last longer, or because they can afford to have a second/third car in the garage, but not a new one.

[random314]

It might seem like the average age should be 7.5 years but cars that last longer than 15 years will contribute more to the sample than the average car, thus giving an average of 11.