What's in a name?

Unisex names given to babies in the last decade

I’ve been itching to play around with the name data released by the BC Vital Statistics Agency for a while, and after finishing my thesis last month, I finally got a chance to dig in to it. I was most interested to learn about how the distribution of names change over time, particularly gender-neutral names and name variants. This post collects a few of my scattered impressions on:

If you’re interested in playing with the data yourself, the DataBC Catalogue publishes lists of every name given to at least five babies born in British Columbia for each of the last hundred years: see here and here.

First, I looked at the most common names for three decades covered in the dataset: the first ten years (1916–1925), the latest ten years (2006–2015), and the ten years covering my own birthdate (1986–1995). The top charts are very different from generation to generation, so it’s surprisingly easy to pick out your own! The most popular names for girls are as follows:

 1916–19251986–19952006–2015
1MaryJessicaOlivia
2MargaretSarahEmma
3DorothyAmandaSophia
4HelenAshleyEmily
5ElizabethJenniferAva
Popularity of three chart-topping names over time

By graphing the frequency of a given name over time, we can see how its popularity waxes and wanes. Some of today’s favourite names, like Olivia or Ava, were totally unknown a century ago. Conversely, some once-common names are now extinct: Jean (#6 in 1916–1925), Marjorie (#12), Phyllis (#15), and Gladys (#18) did not make the most recent list. A few names, like Mary, Elizabeth, Emily, and Sarah, have enjoyed a relatively stable lifespan; others, notably Jessica, Jennifer, and Brittany have gone through a dramatic rise and fall.

The top boys’ names are also generationally distinctive and fun to look at!

 1916–19251986–19952006–2015
1JohnMichaelEthan
2WilliamMatthewLiam
3RobertChristopherJacob
4JamesRyanLucas
5GeorgeKyleBenjamin
Popularity of three more chart-topping names over time

Compared to the girls, the most popular boys’ names generally have longer lifespans. Although the 1916–1925 list contains a couple archaic names — Harold (#17) and Norman (#18) among them — quite a few have maintained a stable baseline of popularity. William, James, Thomas, David, Andrew, and Alexander make the top 50 on all three lists. In other words, there appears to be less variance from year to year in the names given to boys as compared to girls. This may be because there is simply less variety in male names overall: even within a single year, the top names account for more baby boys than girls.

I’m quite curious about the historical prevalence of unisex names. There a few different ways one could rank names across sexes; the following lists names in decreasing order according to the number of male births or female births, whichever is smaller.

 1946–19551986–19952006–2015
1LeslieTaylorQuinn
2TerryJamieRiley
3DaleJordanAvery
4RobinMorganTaylor
5KerryDevonCharlie

Almost all names in the dataset were exclusive to one sex until the 1940s, when several previously-male names started being used for girls as well. This pattern is well-illustrated by Leslie: it was only given to boys when Leslie Nielsen was named, had become common among both sexes by the time Leslie Caron was born, maintained a lower but stable level of popularity for a period spanning the births of Feist and Leslie Odom Jr., and has since gradually faded away.

In the meantime, the popularity of Taylor spiked. In fact, Taylor was popular enough to make the top fifty on both lists for 1986–1995.

The current leading unisex name, Quinn, has actually had a relatively constant level of popularity, but the ratio between boys and girls has shifted over time. It will be interesting to see how the rest of this name’s life cycle will play out!

Name variants

When considering gender-neutral names, the above lists only tell part of the story. Vital Statistics only records people’s names at birth, not their eventual preferred name. This means that the half-dozen people I know of as “Chris” show up in different rows of the dataset!

I expect the most commonly used gender-neutral names in practice are shortened forms of names with several variants, but it’s hard to tell from the data; we can only get an impression from visualizing variants of a given name. I found fourteen names — each exclusive to one sex if you go by birth certificates — that could plausibly be shortened to Chris. In aggregate, they make a remarkably gender-balanced family!

Distribution of "Chris" and its variants overall (top) and over time (bottom)

The long tail of names

Interestingly, female variants of Chris are larger in number and more balanced in popularity than their male counterparts. Is this indicative of something about the overall distribution of names? Tentatively, the answer is yes!

Over the last ten years, the list of boys’ names is shorter: the dataset lists over two hundred more female names than male! The distribution is also more top-heavy for the boys, with the most popular names accounting for more total births.

A rank-frequency plot of names given to babies in 2006–2015

However, male names are getting more evenly distributed over time, which can be seen by plotting the (surprisingly large!) share of newborns given one of the ten most popular names for their sex and year of birth.

Share of the top ten names over time

(As raw birth data is not available for all years, the above chart assumes that names in the dataset represent a constant proportion of the total number of births in each year, based on the 2015 figure.)

Questions