Empirical expression is a descriptive view that describes what the world is. Normative expression is an attempt to describe how the world should operate, which is imperative. For example:
Empirical statement: Issuing tradable pollutant discharge permits can effectively control pollutant discharge.
Specification: The government should issue tradable pollutant discharge permits to enterprises.
Extended data:
Empirical expression and normative expression are basically different, but in one's mind, they are usually interrelated.
In particular, people's empirical views on how the world works will affect their normative views on what policies are desirable. If A's statement that the minimum wage law leads to unemployment is correct, it will deny B's conclusion that the government should raise the minimum wage. However, people's normative conclusions can not only be based on empirical analysis, but also involve value judgment.