For 2021 SIPP, updates were made to the universes of the monthly state (TEHC_ST) and metropolitan status (TEHC_METRO) variables to improve accuracy and consistency. Specifically:  

-   For monthly state (TEHC_ST), the SIPP metadata correctly indicated all persons, THHLDSTATUS in (1,2,3,4), as in-universe prior to 2021 SIPP. However, the corresponding status flag (AEHC_ST) incorrectly indicated not-in-universe (AEHC_ST=0) when TEHC_ST was 60 or 61 (denoting “Puerto Rico and U.S. Island Areas” and “Foreign Country”, respectively). In 2021 SIPP, records where TEHC_ST was 60 or 61 correctly received in-universe values for status flag AEHC_ST.

-   For monthly metropolitan status (TEHC_METRO), the SIPP metadata incorrectly indicated all persons, THHLDSTATUS in (1,2,3,4), as in-universe prior to 2021 SIPP. Persons living in the fifty states, District of Columbia, or Puerto Rico were in-universe, while persons living in the U.S. Island Areas or foreign countries were not-in-universe. As of 2021 SIPP, the TEHC_METRO universe was redefined as only persons living in the fifty states or District of Columbia, TEHC_ST in (1:56), and status flag AEHC_METRO values and the codebook metadata and were updated accordingly.

-   For 2021 SIPP, not-in-universe records for monthly metropolitan status (TEHC_ST in [60,61]) were coded as not-in-universe on TEHC_METRO and received status flag values of AEHC_METRO=0. Along with this update, the TEHC_METRO=3 narrowed the definition from “Not identified or uncoded” prior to the 2021 SIPP to “Not identified” in 2021 SIPP and later.

Data users should be aware of these updates when making comparisons related to in-universe information for state or metropolitan variables with 2021 SIPP and later data against earlier years.