The classical dichotomy is useful for analyzing the economy because in the long run nominal variables are heavily influenced by developments in the monetary system, and real variables are not. true or false?

The answer is: True

Explanation:

First of all, the classical dichotomy in economics assumes that real variables of the economy such as output of goods and services and real interest rates are not influenced by what happens to their nominal counterparts, such as the monetary value of output and nominal interest rate.  It doesn´t consider inflation or the nominal supply, in other words money supply is neutral in the economy (because its value is adjusted to inflation).

The real problem with this theory, at least in the short run, is that in real life money supply, interest rates and inflation do affect the GDP of a country. When the money supply of an economy is increased then aggregate demand also increases. More money equals more demand. That happens because the prices of goods and services doesn´t adjust as fast as a change in the money supply. Also this theory doesn´t consider the monetary circuit theory about money being "created" by the banking system every time a loan is made.