Here’s another post about baby names (I know, I just can’t resist). This time I’ll look at big year-to-year increases (and decreases) in popularity.
The metric I’ll use is raw increase in the number of babies with a given name. For example, there were 5615 Sarahs born in 1970, and 5845 the next year, that’s an increase of 230. I’ll use the raw number (230) rather than percentage (4.1%), because percentage exaggerates changes to obscure names. If the boys name “Renner” goes from 5 occurrences in one year to 40 in the next, it’s not really much of a trend; only 35 more people gave their kid that name. But that calculates as an 800% percent increase. “Renner, the fastest-growing name in America!” In one sense, technically correct, but meaningless.
That said, I do need to account for the number of babies born in each year. Otherwise, a year like 1946, which saw a 30% increase in births from the previous year, will result in spurious results. Yes, there were a ton more Roberts born in 1946 vs. 1945, but only because there were tons more babies born (because of the end of WWII), and not because the name was more popular.
This table lists the largest increases in popularity from the previous year1The final column shows the raw increase, but the list is sorted by increase/total_births.
| Name | Year | Babies that year | Babies the previous year | Increase |
| Linda | 1947 | 99,693 | 52,710 | 46,983 |
| Shirley | 1935 | 42,356 | 22,844 | 19,512 |
| Deborah/Debra | 1951 | 59,120 | 35,242 | 23,878 |
| Ashley | 1983 | 33,295 | 14,857 | 18,438 |
| Jennifer | 1971 | 56,780 | 46,157 | 10,623 |
| Jason | 1973 | 46,685 | 37,441 | 9,244 |
| Michelle | 1966 | 27,153 | 16,213 | 10,940 |
1947 Linda is the winner, by a huge margin. Linda’s popularity was already skyrocketing in the 1940s; 1947 was when she hit the afterburners and passed up Mary as the #1 name in the country (knocking Mary from the spot she had held for 33 years). Why Linda? Here’s a great post about the Linda phenomenon.
Shirley in 1935? Yes, that’s the Shirley Temple effect. As for Deborah and Debra, here’s an interesting post from a wonderful site about baby names. And Michelle was already on the way up, but the Beatles’ song accelerated her rise. The other names on the list (Ashley, Jennifer, Jason) don’t have a singular cause – they were just general fads.
What about the down side? Lets look at names that have lost the most popularity in a single year.
| Name | Year | Babies that year | Babies the previous year | Decrease |
| Shirley | 1937 | 26,820 | 35,163 | -8,343 |
| Deborah/Debra | 1957 | 82,823 | 96,129 | -13,316 |
| Linda | 1950 | 80,431 | 91,019 | -10,588 |
| Jennifer | 1985 | 42,655 | 50,560 | -7,905 |
| Lisa | 1970 | 38,964 | 45,028 | -6,064 |
| Amy | 1977 | 26,732 | 31,341 | -4,609 |
| Jason | 1981 | 41,932 | 48,170 | -6,238 |
A familiar set of names, no? There’s remarkable consistency between the “fastest increase” and “fastest decrease” names. Let’s think about why for a minute. First, in order to lose a lot of popularity, you have to have it in the first place. Obscure names aren’t going to be on this list – you have to near the top of popularity to be in the position of losing it. In fact, a name can be losing popularity and still be popular: in 1950, Linda’s popularity dropped 11%, but it was still the most popular girls name by a large margin.
Second, the same attributes that make a name shoot up quickly will tend to bring it down just as quickly. Fads are like that.
