After I wrote about how well-off millennial renters are the biggest demographic in the Cook County housing market, someone asked me: What do all these people do, anyway, to afford such nice apartments?

I started with the American Community Survey. Six industries had median incomes above $70k in 2014. Overall, employment change in those industries has been positive, and the industries with positive growth shouldn't be terribly surprising—health care, computer and mathematical occupations, and management.

Jobs Paying More than $70,000

Occupation Number of jobs in Cook County
Legal occupations
2014 median income: $105,088

34,782 (-1.6%)

Management occupations
2014 median income: $78,467

200,674 (+1.61%)

Computer and mathematical occupations
2014 median income: $77,745

61,031 (+16.06%)

Law enforcement workers including supervisors
2014 median income: $76,448

21,428 (-5.04%)

Health diagnosing and treating practitioners and other technical occupations
2014 median income: $74,832

70,466 (+18.12%)

Architecture and engineering occupations
2014 median income: $73,334

28,571 (-4.54%)





Source: U.S. Census Bureau

I also looked at employment change in industries where the median income is less than $50k in 2014. (A side note, but a telling one: they weren't the same industries in 2009. In 2009, Construction and sales had median incomes over $50k in 2014 dollars; in 2014, they had median incomes below $50k.) Employment fell precipitously in construction, office and administrative support, and production. It wasn't all bad news—employment in transportation grew substantially—but the ACS data suggests a decline in lower-middle income workers.

Jobs Paying Less than $50,000

Occupation Number of jobs in Cook County
Sales and related occupations
2014 median income: $48,637

166,225 (-5.61%)

Installation, maintenance, and repair occupations
2014 median income: $46,513

45,118 (-7.19%)

Construction and extraction occupations
2014 median income: $45,485

54,490 (-24.63%)

Health technologists and technicians
2014 median income: $45,027

22,770 (+1.02%)

Community and social services occupations
2014 median income: $44,418

30,905 (-0.11%)

Transportation occupations
2014 median income: $41,456

66,145 (+22.01%)

Fire fighting and prevention, and other protective service workers including supervisors
2014 median income: $41,012

25,953 (+2.17%)

Office and administrative support occupations
2014 median income: $39,520

232,459 (-5.39%)

Production occupations
2014 median income: $32,304

119,308 (-9.33%)

Healthcare support occupations
2014 median income: $29,733

31,067 (+15.32%)

Material moving occupations
2014 median income: $29,325

45,056 (+1.6%)

Building and grounds cleaning and maintenance occupations
2014 median income: $26,768

57,237 (-5.16%)

Farming, fishing, and forestry occupations
2014 median income: $26,119

1,409 (-18.93%)

Personal care and service occupations
2014 median income: $25,595

44,522 (+9.81%)

Food preparation and serving related occupations
2014 median income: $23,345

68,749 (+5.71%)





Source: U.S. Census Bureau

But that doesn't account for age, obviously. For that, I used the powerful IPUMS (Integrated Public Use Microdata Series) database at the University of Minnesota's Population Center to slice up the numbers for millennial renters in the city of Chicago.

First, how many people in this age group are choosing to rent versus buying? I looked at people ages 25-34 with 2014 incomes of more than $75k, $100k, and $200k, via the 2014 American Community Survey, as compared with similar groups from 2009 (adjusting income for inflation).

2009, $68k+ 2014, $75k+ 2009, $91k+ 2014, $100k+ 2009, $181k+ 2014, $200k+










The number of these high-income 25- to 34-year-olds is down overall (though it's more of a wash if you don't adjust the incomes for inflation). But dwelling habits have changed; a majority go from buying to renting, except at the top of the income bracket, where the most well-off millennials are more likely to buy than rent.

This seems to line up with what Chris Hagan and Daniel Kay Hertz have observed: In some of Chicago's wealthiest neighborhoods, lower-density apartment buildings are being torn down for single-family homes or luxury condos. Meanwhile, reasonably well-off but not wealthy younger adults are opting to rent, creating a market for the kind of high-end transit-oriented development John Greenfield writes about in Streetsblog today.

So what do these millennials do to make so much money? Again, I queried the IPUMS database, using the 2014 and 2009 ACS data. Here's what 25- to 34-year-old renters with individual (not household) incomes of $68k or more, again adjusting for inflation, were doing in 2009. I limited it to occupations with about 1,000 people.

Occupation Total employed
Lawyers/Judges 3,870
Securities/Commodities/Financial Services 2,553
Computer systems analysts 1,530
Management analysts 1,450
Marketing and sales managers 1,275
Sales reps, services, other 957

Now, from the 2014 ACS:

Occupation Total employed
Management analysts 2,532
First-line supervisors of non-retail sales 1,718
Sales representatives 1,634
Marketing and Sales Managers 1,557
Misc. managers 1,557
Computer software engineers 1,386
Lawyers/Judges 1,328
Production/planning clerks 1,019

First, there are now more occupations representing 1,000 or more renters, because there are more renters. And the changes seem to reflect broader economic trends. There are way fewer lawyers—in 2010, Crain's reported that "a parade of notable law firms in Chicago has laid off attorneys in the midst of the recession." There are more management analysts—in 2013, Crain's reported that "it's a good time to be in the consulting business." Marketing and sales managers held strong—last year, Forbes reported that "Chicago is still known as the place for finding the geniuses of the consumer packaged goods marketing sphere."

Based on the ACS data at least, Chicago's spate of high-end apartment development doesn't seem to be coming so much from more well-off younger adults, but from changing preferences in the housing market. If the Emanuel administration's planned downtown zoning changes go through, they'll have even more options closer to the city center, where 90 percent of its job growth came from 2002-2014. What remains to be seen is if the city can lock them in as residents, whether or not they're renters.