Don't be alone this Hanukkah! - a handy guide on the names of Jewish singles

It was one of those rare times I joined my friends at a bar in downtown Fort Lauderdale. After several dances with an especially attractive woman, my friend returns to our table, dejected.

"Not Jewish," he says.
"How do you know? Did you ask?" I reply
"Of course not! You can't do that," he retorted. "Anyway, her name is Tiffany. Have you ever met a Jewish woman named Tiffany?"
"Also, she's blonde." my other friend added thoughtfully.

Frequency of names always fascinated me. For better or worse, I was always the only Yoav in school, or even the entire world for all I knew. On the flip side, most of us have more than one friend named David, John, Ashley, Lauren, or Miguel. The Social Security Administration tracks names for babies born each year, and many data scientists have used this readily available information to note trends for certain names and decades. But, where can we find information specifically about Jewish names?

I'm glad you asked. The answer is JSwipe, a popular dating application for Jews. In what was no small feat, I manually collected the names of 1000 Jewish men and 1000 Jewish women (yes, there are at least this many gefilte fish in the sea), aged 18-40, in the South Florida area - from West Palm Beach to Boca Raton to Miami. I also noted the ethnicity of users, either by name origin or other profile details. Get ready to swipe right on my findings:

1. The top female Jewish name is Jessica. For men, Michael and David are tied at #1

The bar graph I constructed shows the top 20 names for both genders:

 

2. Israeli Men Really Need Your Love

While going through profiles, I noticed a definite peculiarity: there are almost twice as many Israeli men on the app than there are Israeli women. If you're a woman looking for men on JSwipe (or rather, having men aggressively look for you), there's a 1 in 7 chance you're swiping on an Israeli, with the most common names being Tal, Avi, and Yossi. If you're a man looking for women, about 1 in 13 are Israeli, with the most common name being Yael. 

While American followed by Israeli names were by far the most common, I also identified three other distinct groups of name origin: Latin (from Brazil and Spanish speaking countries), Russian and Eastern European, and Ashkenazi Orthodox (Hebrew names that are not popular in modern Israel, such as Bracha or Mendel). The breakdown is represented in these two graphs: 

3. Men's names are slightly more top-heavy, and women have more unique names

Out of 1000 people, there were 417 unique names for women, and only 324 for men. The fact that there are seemingly "less" male names corresponds with the finding that, compared to women, the top 10 male names are more common (taking up 27% of all male names) than the top 10 female names (which constitute 22% of all female names):

Men:

 Women:

This means that by yelling "hey David, Michael, Daniel!" into a synagogue of 100 men, you should expect an average of 11 people to turn around. In fact, according to the binomial distribution, there's a 99.9% chance that at least 3 people will answer.

For women, however, you might have to shout one more name to achieve the same feedback, and this disparity grows the more names you try to guess.

update: after discussion of these findings, I've had it pointed out to me that male names tend to be more traditional (and often biblical) as opposed to female names (of which there are less in the Bible), which change more quickly and are more likely to be considered "modern". This is certainly an interesting observation.

4. There are too many Bretts

Seriously. I had to swipe through 11 Bretts? Yeesh. 

5. It's interesting to compare Jewish names against the general population

Which names are more Jewish? Which names are less Jewish? I've analyzed data from the general population against the Jswipe data set to find this out. Here's a graphical summary of selected names:

And there you have it.

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I hope all of you have an extremely happy and joyful Hanukkah. And to my non-Jewish friends, which almost certainly include one Tiffany who danced with us at Rhythm & Vine last week, I'd like to wish a Merry Christmas and a Happy New Year.

Yours,
Yoav

It's Always Sunny in Miami, and Not So Much in Boston

My old roommate and I were involved in a vicious feud. You see, he liked to open the windows when it was warm out; however, he always neglected to go back and close them when it inevitably got cold again. This resulted in me shivering for a few hours before I realize that, while it was 75 degrees only a day ago, it's now 55 degrees and I should really put on some pants.

 The essence of the problem can be described in visual form:

This is a common problem for anyone who's lived in New England, where any Uber trip between April and June is likely to involve complaints about the weather. 

Just how common is this problem? I set out to find just how fickle the daily temperature is among the top 25 US cities. In choosing these cities, I used a combination of metrics: population, GDP, and net migration. The analysis was done using the statistical software R, with weather records from Weather Underground. (For a more detailed, technical view of how I worked with the data, click here)

I first set out to find the variance of the weather for these cities as a measure of volatility. I used daily high temperature data for all 366 days of 2016 (a leap year). I ranked the cities by their temperature variance, in descending order, below:

But what does this really mean? Variance is defined as the squared sum of deviation from the mean. In other words, a high variance in this context would mean that a city has many days in which the temperature is much different than the average temperature for the entire year. This could mean many days of ping-pong hot and cold weather, or simply a very pronounced changing of the seasons. Let's look at a temperature graph of a few selected cities. I've ordered them from high to low variance:

       

We see that cities with high variance, such as Minneapolis and Denver, have temperatures that reach a wide range throughout the year, and while there's a definite pattern (cold winter, warm summer), there are still sharp week-to-week and sometimes day-to-day changes - see Boston's dip to a high of about 60 degrees in July and then a jump to the 90s a week after. On the flip side, cities with extremely low variance such as Miami and San Francisco have much flatter, lower-amplitude graphs. Amazingly, Miami's daily high temperature hovers between 72 and 92 degrees Fahrenheit a full 90% of the year!

This doesn't fully answer my original question - in which cities are you most likely to experience the frustration of making a completely new daily evaluation of your window openings, how many layers to wear, and whether or not to finally put away your winter clothes for good? To answer this, I've calculated the temperature swings of each day over the previous day. I've chosen a difference of +/- 10 degrees as an arbitrary metric for "pain-in-the-butt-weather". Let's see the results:

So, almost every third day in Boston seems to be a jump in temperature. However, in Miami, you can paint a pretty accurate weather forecast of tomorrow if you've been outside today. I guess now we know why Pitbull is so happy.

PS -I also calculated the number of days in a year with a 20+ degree temperature swings. Denver leads with 21, but almost all cities have 10 or less of these days (Miami and San Francisco have 0). So, if you wake up one morning and it's 20 degrees colder or hotter than the day before, do note that this is pretty rare, and therefore definitely merits complaining (I'll be here to listen!)