refers to the expenditure or consumption covered by the most detailed level of stratification of the HICP and within which reliable expenditure information is not available for weighting purposes
The coverage of the existing consumer price indices produced by the Member States, practices followed for the inclusion of newly significant goods and services, procedures for adjusting prices for quality changes of the items priced, methods of combining prices to form price indices for elementary aggregates, or sampling methods and practices for obtaining prices differ between Member States to the extent that the resulting consumer price indices produced by the Member States fail to meet the comparability requirement necessary for the production of the HICP.