Here are some gems from this week’s mailbag.

I’m hunting for summer jobs, and I’m curious which sectors most college students or summer workers are employed in.

— Soren Trimble in Springfield, Va.

What a seasonally appropriate question! After ransacking the Bureau of Labor Statistics vaults and crunching millions of numbers, we’ve emerged with an infuriatingly glib answer: To find the jobs that hire the most younger workers, just look for the ones that pay the least!

By definition, student workers haven’t acquired all the job skills they’ll need and often can’t commit to more than a summer or a semester. They look to be stuck in churn-happy, pay-averse sectors like bowling alleys, where 40 percent of the workforce is under the age of 21 and most young workers are still in high school. College kids are easier to find in shoe stores and what we’d call “other lodging,” a category that includes RV parks, camps and — perhaps most relevantly — dormitories.

But those are some narrow niches. Realistically, one colossus stands astride the youth-employment landscape. And it’s probably shaped like a 30-foot-tall rotating hamburger.

More than a quarter of working youths are in food service. More young people sling hash than work in the next eight top youth-employing sectors combined. (Those would be construction, supermarkets, warehouses and dollar stores, recreation, colleges, clothing stores, elementary and secondary schools, and child care.)

Almost a third of restaurant workers are youngsters, and that share soars when you consider the host or hostess. Almost 70 percent of restaurant greeters are 21 or younger, and they’re usually high school students. College students, on the other hand, tend to be servers. The back of house splits fairly evenly, though high-schoolers rule the dish pit.

Of course, we’re estimating here. We’re using the Current Population Survey (CPS), one of the greatest data sources this squishy little species has ever produced, albeit one that will be somewhat diminished in future years. BLS recently announced that it will be cutting the sample size by about 5,000 a month, to 55,000 households, due to budget concerns. Anyhow, irreplaceable as it is, the CPS doesn’t mark someone as a student if they’re on summer vacation. So we had to look for folks age 18 or younger who have attended at least some high school, or those 21 or younger who have attended at least some college.

Food service also exposes the hidden pecking order among high school and college workers in another way. When jobs are scarce, as they were after the Great Recession, college-age workers ruled the restaurants. But in our current ultrahot labor market, when college kids can get better jobs in, say, health care or trucking, the food-service high-schooler quotient has soared.

Of course, food service is an exceptional gig for youths in one way: It’s not particularly seasonal. It employs so many Americans — and burns through them so fast — that it can easily absorb the summer influx. The jobs with the biggest summer hiring surges are actually RV parks and camps, golf courses and marinas. Sports, racetracks and sightseeing would also be good bets.

And if you’re just craving a job with wild seasonal swings, regardless of when they hit, we can recommend ski areas, which peak in January, and tax preparation, which spikes in February.

Who chooses a yellow phone case? Or no case at all?

Is the color of a phone case correlated with any demographics? This week I helped my 90-year-old mother replace her iPhone and get a new case. She chose a school bus yellow case because it would not be mistaken for some else’s phone. Yesterday at her book club she saw that three other 90 year-old women had done the same thing.

— Philip White in St. Paul, Minn.

We can say it’s not just book-clubbing Midwest mothers! Our all-time favorite case, now outmoded and out of stock, was what we will now call nonagenarian yellow. As serial phone misplacers, we picked the easiest hue to spot when overturning a bedstead or streambed in search of a missing (and ringing) phone.

But we’ve heard that a sample size of one — or five, if we count our new book club buds — may be less than ideal. So we called in the big guns. Or, if we’re being honest, perhaps the too-big guns: YouGov, a top pollster that people trust to report the direction of our democracy, almost immediately agreed to ask more than 1,000 Americans the color of their go-to cellphone case.

Well, the numbers are in, and apparently there’s some truth to all that “sample size” and “random sampling” jazz. Yellow was the least popular cellphone case color, unless you count the young woman who wrote in “care bears or a cute bunny with patterns.”

Black crushed the competition with 37 percent of the vote, cruising on the support of 54 percent of men (versus 22 percent of women) and 45 percent of Black Americans. Clear, blue and patterned were the only others to even sniff double digits. Tan, orange and yellow were so unpopular that they rounded to zero percent.

To further dismember our book club thesis, only 16 percent of you said spotting your phone more easily is one of the reasons you use a phone case. Even worse, that answer was actually less common among folks over age 45, a group that also leaned toward the default, omnipresent black case. Almost all of us say we pick cases to protect our phone from damage (89 percent) and/or to make the phone easier to hold (30 percent).

But that’s only among folks who have cases. When we hassled our Tech Friend Shira Ovide, perhaps the planet’s most prominent expert on the tech issues of folks in their 90s, she asked a more important question: Who are those monsters who don’t use a case at all?

Well, whoever they are, they’re rare: 72 percent of us always use phone protection. Just 13 percent own a phone without a case, and another 2 percent own the case but “never” or “rarely” use the darn thing. (Just 3 percent don’t own a cellphone.)

As Shira guessed, men are more likely to go caseless than women, albeit slightly, but the true determinant appears to be age. The older you get, the less likely you are to use a phone case, with retirees making the risky pick at several times the rate of their friends under 30 years old.

Why go caseless? To find out, we uncased our Samsung phone. Again, the sample size is small, but we have to admit that it’s seductively novel to use a phone that feels like a $1,099 piece of electronics rather than an $11 piece of plastic.

Then again, the novelty may wear off when we inevitably join the unfortunate West Coast woman who told YouGov that she bought a red case “after dropping a brand new phone on my cement driveway … 🤬.”

Most common jobs in the United States

Most common jobs in United States? Least common? Private sector vs. public sector? By state?

— Greg Kleffman in Hilton Head Island, S.C.

Thank you so much, Greg! It’s been a long week, and it’s about time somebody lobbed a fastball straight up the middle instead of asking about, like, the politics of reptile owners. (They’re twice as likely to be Republican, 4 percent to 2 percent, but it’s an understandably small sample, so take it with a grain of salt.)

If you guessed home health and personal care aide was American’s most common job in 2023, you were correct! And honestly, if you guessed retail clerk or fast-food counter worker, we ought to give it to you anyway. With about 3.7 million workers each, the three jobs cluster together so closely atop the list that the winner falls within the minuscule margin of error produced by the BLS’s critically acclaimed, clunkily named Occupational Employment and Wage Statistics program.

Twice a year, BLS contacts more than 180,000 businesses to find out what sort of workers they employ in 800-plus occupations and what they pay them. Each year’s final release is informed by the most recent three years of surveys, so when all is said and done, this survey tries to get data from more than half of American jobs.

And it turns out that only 260 of America’s jobs go to wood patternmakers — making it the least common job tracked by the federal government. Brad Moore, director of engineering at Badger Alloys, employs two of them.

On the western edge of Milwaukee, where Badger has sprawled across several city blocks since its founding in 1966, the pattern perfectionists take the engineer’s plan for a valve or pump and craft a master. Often it’s wood, but sometimes they use other materials, such as urethane or aluminum. A colleague puts each side of the master into a mold box, a fancy industrial sandbox full of easy-to-shape industrial sand, to create a mold. They fill the mold with molten steel or alloys. Once it hardens, Team Badger busts the metal out of the sand to reveal single-piece parts that can weigh as little as a few pounds or as much as a late-model Chevy Suburban.

“It is unquestionable that those who can build, maintain and understand traditional wooden pattern equipment are artists,” Moore told us. “We aren’t making more, and they are slowly retiring and leaving the industry” now that so much American manufacturing has moved overseas.

But Moore doubts the art will die off entirely. American factories, ships and power plants, especially those critical to the nation’s security, will always need locally made steel bits that can’t easily be fabricated with other techniques. A few of the 10,000-odd wooden masters in Badger’s dry and secure storage facility have been around for a century, and Moore sees no reason we won’t need them for a century longer.

“Steel castings are absolutely everywhere,” Moore told us. “They impact every single person in their day-to-day lives, and nobody knows it.”

Speaking of impacting everybody in their day-to-day lives, the most common public-sector jobs are elementary school teachers, followed by teaching assistants and high school teachers. Only police officers break educators’ stranglehold on the top five. Of course, those jobs tilt overwhelmingly toward local government. The most common state-government jobs are corrections officers and registered nurses. For the feds, it’s mail carriers.

The most common job in more than a dozen states and territories is fast-food worker. But from there, patterns start to break down. For example, home health aides predominate in many aging northern states, but also in retirement destinations such as Arizona and California. Laborers rule in some of Appalachia, but also in logistics-heavy New Jersey. D.C. is the only place where the beguilingly named “business operations specialists, all other” rule the roost.

While Greg the Reader didn’t ask about the highest- and lowest-paying jobs, we’re stone-cold certain the rest of you will! This source isn’t as exhaustive as the tax data we used for doctor pay. It’s reported by employers, and only counts wages and salaries, but it has the advantage of addressing almost the entire economy and providing medians in addition to averages, which can be skewed upward by high earners.

No matter how you slice it, physicians and dentists still come out on top, with median salaries above $220,000. But airline pilots ($219,000), nurse anesthetists ($213,000) and chief executives ($207,000) also do okay. Hosts and hostesses, fast-food cooks and amusement-park attendants do not — they pocket around $29,000 a year.

Anyway, hi there! The Department of Data craves questions. What are you curious about: Have vaping bans changed teens’ habits? Who self-identifies as a “redneck?” What other cultural classifications can we find (and measure) along those lines? Which states’ residents are most eager to secede from the union? Just ask!

If your question inspires a column, we’ll send you an official Department of Data button and ID card. This week’s buttons go to Soren, Philip and Greg! Please keep those cards and letters coming!