PBA Home > Institutional Research & Analysis > Students > Student Zip Codes, 1993 to present

Where students live during school, fall census 1993 to present

Where students live during school, 1993 to present, by undergraduates, graduates and all students. All information below pertains to the creation of this document.

Faculty and staff zip codes

Also see zip codes of faculty and staff for 2001 to present.

Findings of interest

• Local zip codes in 2009 are available for 82% of undergraduates (increase from 63% in 2008) and 95% of graduate level students.
• Including residence halls, 72% of undergraduates lived in the city of Boulder as did about 67% of graduate level students.
• NOT including residence halls, the percentage of all students who live in Boulder has fallen from 81% in 1993 to 61% in 2009.
• For undergraduates and graduate level students, respectively, the in-Boulder percentages not including residence halls are 85% undergraduates and 72% graduate level students in 1993; 59% undergraduates and 66% graduate level students in 2009.
• Over time, the largest increases in numbers of students are in the cities along U.S. Highway 36 - Louisville, Superior, Broomfield and Westminster. Longmont has also seen a sizeable increase in students.
• The percentage of faculty/staff living in Boulder has decreased each year from 2001 (50%) to 2009 (41%).
• The percentage of TTT faculty living in Boulder has also decreased. 72% in 2001 to 64% in 2009.

Commuting zip code range

We defined a range of zip codes of plausible places a student could live in and commute to UCB. We took the first three numbers of the zip code to define this range (800 through 806, plus 809). These zip codes cover cities from Fort Collins to Colorado Springs and Breckenridge to Brighton. We realize that someone could live outside of this range and commute to classes a few days per week, but we've judged it more likely that addresses outside the range are actually home/parent addresses, than the during-school local address of part-time long-commuting students. We also realize that some of the zips included (e.g., Colorado Springs) would be a really long way to commute.

Identifying where students live

Students can have addresses of different types on the student records system. If the "mailing" address of the student was in the commuting zip code range then we took that. Otherwise if the "permanent" address was in the zip code range then we took that if the student was a graduate student. If the student was an undergraduate we took the "permanent" address only if the student lived in a residence hall in the four years prior to the check, and the current "permanent" address is different from the "permanent" address when the student lived in the residence halls. For 2001 and later, the zip code from personnel files was used last if the student's University of Colorado employee zip code was in the defined range. Otherwise we set the student's zip code to be unknown. Examples

• Sally, mailing 80302, use 80302
• Jerry, grad student, no mailing address in range, permanent 80304, use 80304
• Connie, law student, no mailing address in range, permanent in Texas, no zip used (unknown)
• Tom, undergrad, no mailing address in range, permanent in New Hampshire, no zip used (unknown)
• Bret, undergrad, no mailing, permanent 80304, lived in a res hall 3 years ago, permanent zip in California when lived in the res hall, take 80304
• Robin, undergrad, no mailing in range, permanent 80304, lived in a res hall last year, permanent zip 80304 when lived in the res hall, no zip used (unknown)
• Zach, undergrad, no mailing in range, permanent 80304, has not lived in a res hall in the prior 4 years, no zip used (unknown)
• Joe, undergrad, no mailing in range, permanent 80304, has not lived in a res hall in the prior 4 years, employed at UCB, employee zip code is 80304, take 80304.
• Sara, undergrad, no mailing in range, permanent outside range, employed at UCB, employee zip is outside range, no zip used (unknown).

Our rule assumes that if an undergraduate lives in a residence hall (as do over 90% of entering freshmen), then is enrolled after that and is NOT living in a residence hall, the student has not moved back home.

The earliest fall for which could we do calculations is 1993 (reliable residence hall info first available for 1989)

For graduate students, we get no known local address for under 10%, with no change in proportion unknown over time (6% for 1993, 5% for 2009)

For undergraduates, we get a larger proportion of unknown (22% in 1993, 18% in 2009). With an emergency contact system now in place, the university has attempted to make a better effort of obtaining students' addresses. For instance, in 2003, the percent of undergraduates with an unknown zip code was 40%.

A change in method. In analyses done in 2001, we took permanent addresses in the zip range for all students with no mailing address. We now believe that substantial proportions of the addresses we thought were local, and that we used in analysis, were actually parent addresses. Of course the problem was more severe for Colorado residents, many of whom have parents in the Denver-Boulder area in the commuting zip code range.

Adjusting for unknown zips

Our analyses assume that

• The addresses we have selected for analysis are in fact where students live during school
• Students with no selected address are distributed geographically in the same way as those with known addresses. While we have no evidence for this, we have none against either.
• Exception: We assume that no students with unknown zips live in a residence hall. Residence hall addresses are put on student records directly by housing.
• We've calculated "adjusted" numbers for each zip code based on these assumptions. We've simply assigned all students with unknown zips to the zip locations in the same proportion (excepting residence halls) as students with known zips.

Map links

• Northern Colorado
• Maps from the State of Colorado
• Miscellaneous links

Files- l:\ir\reports\guideug\zip\zip*.sas

Last revision 01/27/10