Introduction to IPUMS NYTS and IPUMS YRBSS

Introduction to IPUMS Data overview Harmonization IPUMS NYTS IPUMS YRBSS Accessing data

What is IPUMS? IPUMS integrates census and survey data collections across time and space. Harmonized variable codes and documentation make it easy to study change over time, pool data, and conduct comparative research. Data and services are available free of charge.

IPUMS NYTS and YRBSS IPUMS NYTS and IPUMS YRBSS were produced with funding from the Food and Drug Administration (FDA) Center for Tobacco Products. Funding did not include support for dissemination, so data are not provided through the usual IPUMS data access system. These projects were a collaboration between NORC and IPUMS.

Introduction to IPUMS Data overview Harmonization IPUMS NYTS IPUMS YRBSS Accessing data

Microdata Microdata are composed of individual records containing information collected on persons (or other unit of analysis) The responses of each person to the different questionnaire items are stored in separate variables In contrast, summary or aggregate data are compiled statistics for a pre-selected subgroup or area. Microdata allow researchers the flexibility to generate the specific statistics or tabulations that suit their own research

Example microdata records for 4 individuals Person Number Marital status Education Occupation Person 1 Person 2 Person 3 Person 4

Introduction to IPUMS Data overview Harmonization IPUMS NYTS IPUMS YRBSS Accessing data

What is harmonization? Combining datasets collected at different times into a single, consistent data series Applying a coding scheme that connotes broadly comparable categories while retaining additional detail available in only a subset of years Documenting details about the harmonization process and any potential comparability issues

Example of harmonization Changes to race/ethnicity response categories in YRBSS Pre-1999 Categories 1999-forward Categories Native American or Alaska Native Asian or Pacific Islander Non-Hispanic Black Non-Hispanic White Hispanic/Latino Other Native American or Alaska Native Asian Native Hawaiian or other Pacific Islander Non-Hispanic Black Hispanic/Latino Non-Hispanic White Other

Example of harmonization (cont.) Harmonization creates comparability between codes in pre-1999 and 1999-forward without losing detail from more recent years. Pre-1999 categories with simple codes Harmonized codes 1 = American Indian or Alaska Native 2 = Asian or Pacific Islander 3 = Non-Hispanic Black 4 = Non-Hispanic White 5 = Hispanic/Latino 6 = Other 10 = American Indian or Alaska Native 20 = Asian or Pacific Islander 21 = Asian 22 = Native Hawaiian or other Pacific Islander 30 = Non-Hispanic Black 40 = Non-Hispanic White 50 = Hispanic/Latino 60 = Other

Example of harmonization (cont.) 10 = American Indian or Alaska Native 20 = Asian or Pacific Islander 21 = Asian 22 = Native Hawaiian or other Pacific Islander 30 = NH Black 40 = NH White 50 = Hispanic/Latino 60 = Other The first digit of the code is consistent across all years The second digit of the code contains detail specific to 1999-forward

Example of harmonization (cont.) Variable documentation in the codebook includes codes and labels, notes changes to response categories, and provides additional information about changes to the variable over time, including: the option to report multiple races beginning in 1999, the elimination of the “Hispanic/Latino” as a race category in 2005, how ethnicity information is derived for this variable

Introduction to IPUMS Data overview Harmonization IPUMS NYTS IPUMS YRBSS Accessing data

About NYTS National Youth Tobacco Survey (NYTS) Cross-sectional nationally representative survey of youth grades 6-12 Fielded roughly biannually since 1999 On average, file includes over 20,000 youth each year it is fielded Focuses on youth behavior, attitudes, and exposure to tobacco

IPUMS NYTS Original public use data variable names reflect question number; IPUMS NYTS renames variables so they are consistent over time and reflect what the variable measures Codes are harmonized to increase comparability without losing year-specific detail in the original files IPUMS NYTS includes 10 years of available microdata from 1999-2014 Researchers using IPUMS NYTS microdata should use the following citation: Matthew Sobek and Kari C.W. Williams. IPUMS National Youth Tobacco Survey [dataset]. Minneapolis, MN: IPUMS and Chicago, IL: NORC, 2017. https://doi.org/10.18128/D0XX.V1.0.

Introduction to IPUMS Data overview Harmonization IPUMS NYTS IPUMS YRBSS Accessing data

About YRBSS Youth Risk Behavior Surveillance System (YRBSS) Cross-sectional nationally representative survey of youth grades 9-12 Fielded biannually since 1991 On average, file includes over 14,000 youth each year it is fielded Focuses on health risk behaviors developed during adolescence

IPUMS YRBSS Original public use data variable names reflect question number; IPUMS YRBSS renames variables so they are consistent over time and reflect what the variable measures Codes are harmonized to increase comparability without losing year-specific detail in the original files IPUMS YRBSS includes 12 years of available microdata from 1991-2013 Researchers using IPUMS YRBSS microdata should use the following citation: Daniel J. Backman, Greg Freedman Ellis, Matthew Sobek and Kari C.W. Williams. IPUMS Youth Risk Behavior Surveillance System [dataset]. Minneapolis, MN: IPUMS and Chicago, IL: NORC, 2017. https://doi.org/10.18128/D0XX.V1.0.

Introduction to IPUMS Data overview Harmonization IPUMS NYTS IPUMS YRBSS Accessing data

Available Files Zipped, fixed-width ASCII data file that contains harmonized variables and all years of data. Syntax command files to read fixed width data into: Stata SAS SPSS R Codebook that includes detailed variable descriptions, codes, variable availability over time, and any notes on comparability issues for using the variable over time Zipped directory containing original questionnaires Technical assistance memo Practical weight guidance memo

Unzipping and accessing data IPUMS NYTS and YRBSS data are provided as a single raw ASCII file. To analyze data, users must first download the data and syntax command file for their statistics package of choice. IPUMS datasets are compressed; users must unzip the data file before using it. Additional resources on decompression applications and tips for ensuring your statistical package can identify the correct working directory and data file are available under the “User Support” section of the IPUMS NYTS and IPUMS YRBSS sites. Data users should reference the codebook for variable names and important information on comparability. Users should review the technical assistance and practical weight guidance memos to ensure they fully understand how to weight analyses appropriately.