I was wondering where I can find the commuting data (commuting journey to work worker flows data). What is the smallest geographical unit avalible for Maricopa county.
These variables can be found in the “PLACE OF WORK AND TRAVEL TIME VARIABLES” variable group. You can identify individuals that work in Maricopa county using the PWSTATE2 (value 4 for Arizona) and PWPUMA00 (value 100 for Maricopa county) variables. Unfortunately, this is the smallest identifiable geography available in the Public Use Microdata. Depending on what detailed information you are interested in, you may be able to use the summary tables available through IPUMS NHGIS, which can identify smaller geographic units such as tracts and block groups.
I hope this helps!