what are some of the new approaches to the subject?
Modeling economic policy and political institutions concerning interactions between agents and economic and political institutions.
Political economy
A rather-recent focus has been put on modeling economic policy and political institutions concerning interactions between agents and economic and political institutions, including the seeming discrepancy of economic policy and economist's recommendations through the lens of transaction costs. 
who was harold innis? He was a professor and an author. what subjects did he teach? Political economy. in which university did he teach? University of Toronto. what is the origin of the subject mentioned above? It originated in moral philosophy, to explore the administration of states' wealth, with "political" signifying the Greek word "polity" and "economy" signifying the Greek word "oikonomía" (household management)..
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Political economy [SEP] Current approaches
Empirical analysis includes the influence of elections on the choice of economic policy, determinants and forecasting models of electoral outcomes, the political business cycles, central-bank independence and the politics of excessive deficits. A rather-recent focus has been put on modeling economic policy and political institutions concerning interactions between agents and economic and political institutions, including the seeming discrepancy of economic policy and economist's recommendations through the lens of transaction costs. From the mid-1990s, the field has expanded, in part aided by new cross-national data sets allowing tests of hypotheses on comparative economic systems and institutions. Topics have included the breakup of nations, the origins and rate of change of political institutions in relation to economic growth, development, financial markets and regulation, the importance of institutions, backwardness, reform and transition economies, the role of culture, ethnicity and gender in explaining economic outcomes, macroeconomic policy, the environment, fairness and the relation of constitutions to economic policy, theoretical and empirical.