Summary statistics are aggregated counts of survey or administrative data.
Microdata is survey or administrative data about an entity (person, family, establishment).
Longitudinal or panel study: same group of individuals is interviewed at intervals over a period of time.
Cross-sectional study: data from particular subjects are obtained only once.
There is typically around a 2 year time lag from the time the data is collected to the time of release.
Very little subnational data is available. Most subnational data is restricted when available. We do have a fair amount of state level macro data for the United States. City level data is often of a case study type or only available for very large cities.
Many micro-level datasets are restricted and it is not uncommon to wait a year before getting permission or denial to use the data. Each country has its own rules.
What exists for one country may not exist for another country. Data is generally inconsistent across borders.
Documentation for data is typically in the official language of the country.
Data does not always come with setup files. You may need to write a setup file to read in the data.
Always look at the methodology.
Have data but need help working with the data?
If you already have identified the source of your data or statistics and you need help subsetting the data, preparing the data, or analyzing the data, consultants are available: