political economy vs economic science

political economy and economic science both are nouns.

Word	Noun	Adjective	Verb	Adverb
political economy	Yes	No	No	No
economic science	Yes	No	No	No

As nouns, political economy and economic science are synonyms defined as:

political economy and economic science: the branch of social science that deals with the production and distribution and consumption of goods and services and their management

Other synonyms of political economy include economics.

political economy (noun)	economic science (noun)
the branch of social science that deals with the production and distribution and consumption of goods and services and their management	the branch of social science that deals with the production and distribution and consumption of goods and services and their management