Policy representation has been one of the foremost topics in political
science. The pre-condition is the stability of policy preferences. While
individual opinions may be influenced by many sources, scholars have
found the macro level of opinion to be stable. The disaggregation of
survey data may lead to the problem of a large standard deviation being
encountered due to the small number of observations in some counties.
Therefore, multilevel regression with post-stratification (MRP) is used to