I would have guessed the data used to construct the CPI would be open to everyone.
But no, it appears to be unavailable and it is instead a black box due to rules of confidentiality. What is strange is, it appears much of the data is publicly available data. For example, 8% comes from e-commerce sites, the USPS public website, etc. If you browse through the categories, you can also see that almost all the data could be collected from public sources - APIs, websites, etc.
So, does anyone know why this data cannot be obtained?
Reference: https://www.bls.gov/opub/hom/cpi/pdf/cpi.pdf