The survey datasets linked on this page were collected from only those respondents in the UAS Covid national sample who were residents of Los Angeles County. These LA County respondents constitute a subsample representative of the LA County population.

Each UAS Covid survey is classified as either a long-form or a short-form survey. The short-form suveys were administered only to respondents in the LA County subsample. The long-form surveys were instead administered to the national sample, so each long-form survey dataset that is merged into the LA County longitudinal file and linked on this page is a subset of the matching national long-form survey dataset, keeping only those respondents who are LA County residents.

The first survey, referred to as Wave 1, was a long-form survey that was fielded March 10 - March 31, 2020. The short-form surveys began in Wave 2 as part of the tracking surveys design and from April 1, 2020 - July 20, 2021 (Waves 2 - 29), each wave of data collection for LA County fielded both a long-form and short-form survey.

Each long-form survey in this period was administered to LA County residents once every two weeks during Waves 2 - 24 (which started April 1, 2020 through Februrary 3, 2021) or once every four weeks during Waves 25 - 29 (started February 17, 2021 through June 9, 2021). Each short-form survey was administered with the same two or four week periodicity, but on the alternate weeks (Waves 2 - 24) as the long-form survey or on the alternate two weeks (during Waves 25 - 29). This set-up entails that during Waves 2 - 24, respondents in LA County had only one week to answer a survey, rather than the two weeks allowed for the rest of the country; and that during Waves 25 - 29, LA County respondents had only two weeks, rather than the four weeks allowed during these waves for the rest of the country.

To give an example from Wave 2, if an LA County respondent was invited to the long-form survey on Monday, April 6, then the same respondent was invited to the short-form survey a week later on Monday, April 13. Conversely, a respondent who was invited to the long-form on Monday, April 13 was invited to the short-form a week earlier on Monday, April 6.

The tracking surveys ended with Wave 29 and subsequent waves of the Covid survey were fielded as stand-alone long-form surveys, similar to Wave 1. Wave 30 was fielded from September 23 to October 31, 2021. Wave 31 was fielded from February 1 to March 30, 2022. Wave 32 was fielded from July 20 to September 9, 2022. Wave 33 was fielded from November 18, 2022 to January 15, 2023. Wave 34 was fielded from May 12 to July 9, 2023.

Datasets, questionnaires and codebooks are listed under the Documentation tab. UAS Understanding Coronavirus in America publications in academia, blogs and the media can be found in the Publications tab.

LONGITUDINAL DATA The UAS Covid-19 Los Angeles County Sample Longitudinal File provides a cleaned and harmonized dataset containing all waves of survey data for LA County, with all long-form and short-form surveys. The variable names have been harmonized, allowing easy longitudinal analysis, and the file includes longitudinal sample weights. Consult the file documentation and variable list/crosswalk linked below for more information. For the vast majority of analyses this longitudinal file will be the dataset of choice. For situations where you need weights for an analysis of a individual wave, we provide individual survey datasets, located in the next section of this webpage.


Each wave of the LA County tracking survey is conducted as two individual UAS surveys – the national “long-form” and the LA County “short-form”. These are administered to LA County residents in alternating weeks. Together they create a weekly sample for most of the short-form variables. The individual UAS survey files are combined, cleaned and harmonized in the longitudinal data file linked above, but we also provide the individual files here for completeness, with the sample in the individual long-form files limited to LA County residents. Each data file is individually weighted, to allow stand-alone analysis of the file on its own. To access the full national sample long-form data files, visit the National Survey Data page of this site.