© Copyright 2004 by the Wyoming Department of Employment, Research & Planning


Vol. 41 No. 8    



Worker Residency Determination - Wyoming Stepwise Procedure

by: Sylvia D. Jones, Statistical and Research Analyst

Because of the complexity of worker residency determination, the states of Nebraska, New Mexico, South Dakota, and Wyoming are working together to define a common measure. This article represents the latest methodology as a stepwise hierarchical procedure that removes individuals from further tests as they are determined residents. The four steps in decreasing importance are: 1) Unemployment Insurance claim, 2) Valid Wyoming driver's license, 3) Wyoming community college enrollment, and 4) Wyoming state of origin (SSN). The residency determination is valid for six quarters surrounding a calendar year rather than simply a point in time.

While seemingly a simple concept, Wyoming residency has proven difficult to define. Identifying a working Wyoming resident is particularly important when addressing the related issues of current and potential labor supplies. Our initial definition was published in the November 2002 Wyoming Labor Force Trends (Jones, 2002). Since that time Research & Planning (R&P) has worked closely with Nebraska, New Mexico, and South Dakota to revise our original process. This article outlines the steps involved in the current methodology used to define residents. 

Because the Wyoming labor force is dynamic, we decided to base resident status on a six-quarter period rather than a single point in time. The six quarters are built around a calendar year; regardless of the quarter of interest, residency is based on the calendar year of that quarter and the quarters immediately before and after. For example, a worker defined as a resident in first quarter 2001 (2001Q1) by our methodology would also be defined as a resident in 2000Q4 through 2002Q1. The same is true if the individual was a resident in 2001Q3. This allows flexibility to include those who work in Wyoming seasonally or intermittently.  

The Figure visually outlines the steps involved in residency determination. The Table shows how the flowchart works numerically, using Wage Records for 2000Q4 through 2002Q1. There were 232,431 unique social security numbers (SSNs) in Wage Records for 2000Q4, the starting point for this example. An additional 526 unique claimants filed an Unemployment Insurance (UI) claim as a Wyoming resident but did not have a Wage Record in the reference quarter. Those individuals contribute to the total workforce, but do not affect the count of residents in Wage Records.

Step 1 matched the unique SSNs found in the 2000Q4 Wage Records against the UI Claims files. If the individual filed a UI claim during 2000Q4 and had a claimant state of Wyoming, we classified them as a resident and they were removed from further tests. In our example, 5,207 individuals met this criterion.

The remaining SSNs were then matched against the Wyoming Driver's License file (Step 2). If the individual had a valid license in 2000Q4, meaning they had been issued a license with an expiration date after the test period, we classified them as a resident. This includes those who were issued a driver's license during 2000Q4. A total of 181,753 individuals were defined as residents based on this step.

Step 3 involved matching the SSNs to the community college student files. Individuals who were enrolled in one of Wyoming's seven community colleges during the fall semester of 2000 were considered residents, if their respective schools classified them as such. This step added 529 workers to the resident total.

The last step (4) classified the remaining individuals as residents if they were issued a Wyoming social security number. The first three digits of the SSN reflect the state of origin (i.e., Wyoming’s SSNs start with 520; Computer Professional for Social Responsibility, 2001). Of the original number of workers with unique SSNs in 2000Q4 Wage Records, 9,960 were classified as residents because they originated in Wyoming but did not meet the earlier criteria.

The number of residents from each of the steps were added together to form Level I-A in the Table (197,449). This represents the number of residents in 2000Q4 based on the four criteria. The remainder (Level I-B) was 34,982, representing those not yet defined as residents. The remainder was carried over to 2001Q1 and the steps began again. Step 1 shows that 352 of the remainder filed a UI claim in 2001Q1 and were classified as a resident. In Step 2, we identified 1,476 people who had been issued a driver’s license in the reference quarter. Another 370 were enrolled in a Wyoming community college in Spring semester 2001. A total of 2,198 residents were added to the original 197,449. The 32,784 individuals still lacking residency status began with Step 1 in 2001Q2.

By the end of the six quarters, 203,651 of the original 232,431 (87.6%) were classified as residents. When added to the number of residents claimants without a Wage Record in 2000Q4 (504), we can estimate the available resident work force in that quarter (I-A+a) as 204,177 residents.

Level II shows the number of new SSNs appearing in Wage Records in 2001Q1. The steps for residency determination are exactly the same as for Level I with a final resident count of 17,726 (69.3%).

Levels III through VI are the same as the first levels, each adding unique SSNs appearing for the first time during one of the six quarters of the study period. Line b shows the overall total. Just over 76 percent of SSNs appearing in Wage Records from 2000Q4 through 2002Q1 were residents of Wyoming. When added to the number of individuals who filed a resident UI claim but did not have a Wage Record during the period, we identify a potential workforce of 366,537 people.


Jones, S.D. (2002, November) Defining residency for the Wyoming workforce. Wyoming Labor Force Trends. Retrieved July 26, 2004, from < http://doe.state.wy.us/lmi/1102/a1.htm >

Computer Professionals for Social Responsibility (2001). Structure of Social Security Numbers. Retrieved July 26, 2004, from < http://www.cpsr.org/cpsr/privacy/ssn/ssn.structure.html >


Table of Contents | Labor Market Information | Wyoming Job Network | Send Us Mail

These pages designed by Julie Barnish.
Last modified on by Krista R. Shinkle.