“In those days Caesar Augustus issued a decree that a census should be taken of the entire Roman world. And everyone went to their own town to register.” (Luke 2)
Fast forward 18 centuries and the US Constitution states: “The actual Enumeration [of every free person] shall be made…every subsequent Term of ten Years, in such Manner as they shall by Law direct.” Besides being mandated by law, an accurate census count is important for every local jurisdiction and state. The results of the decennial census are used to apportion Congressional Representatives (and indirectly Presidential Electors) to the individual states. The results are also used to allocate various grants, funding, and other Federal program benefits to states, tribes, and local jurisdictions. Failure to count every person in King County during the 2020 Census could have an impact of millions of dollars for the region over 10 years.
An accurate census is a top priority for King County. Earlier this year King County Executive Dow Constantine appointed Gary Locke, former King County Executive and Washington State Governor, as honorary Chair of a community-led effort to ensure a complete, accurate Census count in 2020. The LUCA program described in this article is an important foundation for an accurate census.
The Local Update of Census Addresses (LUCA) is a collaborative program between the United States Census Bureau and local governments. It provides the only opportunity for local governments to provide input to the Census Bureau to improve the addressing information the Bureau uses to canvas for the 2020 decennial census. King County participates in LUCA because of the recognition every person needs to be counted, and we know the County’s carefully maintained addressing data can improve the accuracy of the data the Bureau will use.
Participation in LUCA requires significant dedication of time and resources. King County wanted to ensure as many jurisdictions as possible participated, so under the leadership of the county’s demographer (Chandler Felt), and the financial commitment of the King County Executive’s Office, staff at the King County GIS Center reached out to cities and tribes to offer their assistance. Ultimately five cities took up the offer (Des Moines, Enumclaw, Kenmore, Shoreline, and Woodinville), and a cooperative effort was undertaken. Many others, recognizing the importance of LUCA, chose to participate on their own. This left King County to review addresses for the unincorporated portions of the county, as well as the five cities.
The LUCA program starts a couple of years before the census is actually conducted, in order to give the Census Bureau time to review and incorporate the local feedback into their data. Earlier this year each jurisdiction participating in LUCA was sent the Census Bureau’s address list. In our case, all of King County. Under Title 13 of the United States Code the Census Bureau is required to maintain the confidentiality of the information it collects, including its address list. This confidentiality requirement extends to the individuals at King County working on the LUCA project. Before an individual can view the data they are required to sign an agreement, indicating they will adhere to the guidelines to keep the address list secure and confidential. Precautions were taken at King County to ensure we complied, including using a dedicated laptop disconnected from any network, which was kept in a locked cabinet when not in use. Only the county demographer, three GIS analysts (Gavin Gray, Paul McCombs, and Mary Ullrich), and the KCGIS Center manager (George Horning) could access the computer and view the data.
The Census Bureau offered special software known as GUPS (Geographic Update Partnership Software) for editing their address list. Built on the QGIS platform, GUPS tightly controls and documents the editing process, and simplifies submittal of changes to the Census Bureau. For these reasons we chose to use GUPS, even though we were warned the large size of Census Bureau’s address list for King County of well over 900,000 records might make GUPS unwieldy. Sure enough it did. However, mid-way through the process the Census Bureau recognized this problem and provided their address list broken down into eight county subdivisions. We worked on each subdivision in turn, and the GUPS performance greatly improved.
Before getting to the actual editing of the Census Bureau data, much work was done to run comparisons between King County data, data we received from the partner cities, and the Census Bureau’s. We looked for any differences, including addresses missing from any source. Ultimately we were able to significantly narrow the focus to a small fraction of the total number of addresses. This greatly improved the efficiency of our review.
Our primary objective was to add verifiable addresses that were missing from the Census Bureau’s list. While we found the Bureau’s data to be highly accurate, we were still able to add over 3,500 addresses for the unincorporated portion of King County plus the five cities. This represented a 2.5 percent increase over the 142,000 addresses in the Bureau’s list. We also looked for addressing errors in the Bureau’s data. For this we corrected nearly 1,500, or just over 1 percent. All of these additions and changes represent residents of King County who could potentially have been overlooked by the 2020 Census.
King County submitted our LUCA changes to the Census Bureau in July. The Bureau will now conduct a review and notify King County of any discrepancies in their findings. The county will have a final opportunity to appeal the Bureau’s LUCA feedback in August of 2019.
This effort would not have been successful without the dedication to the project of the three GIS analysts, Gavin, Paul, and Mary. They were invested in the outcome, and made every effort to provide accurate, complete feedback to the Bureau. The King County Executive’s Office is also to be praised for their willingness to fund the project. Staff at the partner cities were very cooperative in providing us with their addressing data, which was helpful in improving the final submittal. Finally, Chandler Felt, who retired on July 31 after 45 years of service to King County, championed the effort from beginning to end. It would not have happened without his resolve to have the most accurate census possible for King County.