All deprecated commands still work in Stata 18 but will produce a warning. They are scheduled for removal in Stata 19.
For example, you can estimate county-level poverty rates from a state-level survey by borrowing strength from covariates like tax returns and demographic data. implements both direct and model-based estimators (Fay-Herriot, unit-level). Stata 18
To keep the software lean, StataCorp has deprecated a few older commands: All deprecated commands still work in Stata 18
Impulse response of GDP to a 1-unit shock to interest rate lpirf gdp, impulse(r) lags(4) horizon(8) vce(cluster id) unit-level). To keep the software lean