Applied Econometrics lectsure

1. Economists care about standard errors in addition to point estimates as they allow measuring confidence in results. However, standard errors are often calculated incorrectly when observations are not independent or identically distributed. 2. Survey data is often clustered, stratified, and uses sampling weights, violating assumptions of independence and identical distribution. This can lead to standard errors that are too low if not properly accounted for. 3. Robust standard errors that account for survey design are important for many commonly used surveys to obtain accurate measures of confidence in results. Failing to use robust standard errors can result in incorrect statistical inference.