While I was researching my previous article on Cambridge’s population growth, I found that the County Council’s Research Group have some quite detailed projections about the structure of Cambridge’s population, and if you ask them nicely, they will send you a spreadsheet. Indeed they are hoping to publish this sort of data more widely as part of the excellent Cambridgeshire Insight project. Thanks to Alan and Mike at the Research Group for sending me the data for this article.
So, without further ado, here’s what the population structure of Cambridge looks like. Boys on the left, girls on the right, and grouped into one-year bands by age, oldest at the top:
Inevitably, I need to add a couple of caveats here. These numbers are the Research Group’s projections for 2014, based on their available data, with each number rounded to the nearest 50. So they won’t be exactly correct, but they should be pretty close. As you can see, the overall impression is of a sort of wonky sword. The most prominent feature in the data is the cross-guard of the sword – the huge increase in the population at ages 19, 20 and 21. This of course represents the large number of students who come to Cambridge for three years, before mostly disappearing again. There are some other notable features, too – the handle of the sword curves gently inward, indicating that there are increasing numbers of children at younger ages – implying more pressure on the city’s schools in years to come.
Beyond the student bulge, there are some other interesting things going on – the most populous year-group here is at age 29, and there’s a distinct imbalance, with men clearly outnumbering women – more on this in a moment. After the early 30s, the picture is one of gently dwindling numbers up the blade of the sword, and towards the top, women start to outnumber men, quite decisively by the over-90 age group.
Here’s a more detailed look at the gender balance. This graphic shows the male and female percentage of each year-group of Cambridge’s population, according to the projections.
Some of the “noise” in the data here is due to the rounding, but there are a few noteworthy features. The main student years, 19, 20 and 21, are almost exactly 50-50, but from 22 to the early 30s, there is a noticeable shift to the blue side – overall there are 125 men for every 100 women in this age group. Is this the effect of gender bias in Cambridge’s tech-heavy jobs market, or is something else going on? After the mid-30s, the picture is more or less balanced again until age 70, when demographic factors starts to take their toll of the men. However, the Beach Boys’ preferred ratio of two girls for every boy is not reached until age 87.
As with many other things, Cambridge’s population structure is quite different to that of the rest of the county. Here’s what the picture looks like for Cambridgeshire excluding Cambridge:
Firstly, there are a lot more people on this diagram – the rest of the county outnumbers Cambridge by nearly four to one. It’s also noticeable that there’s a dent rather than a bulge at the main student age group, reflecting people going away to University. The widest part of the diagram is for people in the late 40s, though there’s also a sudden step at age 67 – this represents those born in the “baby boom” after the end of the Second World War. As with the Cambridge diagram, there’s a tilt towards the female side of the diagram at the upper end of the age range.
Thanks again to the County Council’s Research Group for supplying me with the data for this article, and I wish them all the best with their work on making more of the fruits of their labours available online.