What are some interesting economic research subjects, that would utilize intermediate macroeconomic principles?

Economic research subjects are as follows:

The Theory of Production: The production theory is an attempt to define the concepts by which a business company determines how much of each material the business unit is to produce. It uses many macroeconomic principles to take decisions related to cost and profit maximization.

Global Conflicts and Economy: This research topic deals with the impact of global economic relations on political conflict, its use, and efficacy of economic statecraft, and the implications of national security concerns on world economic relations. It is a worldwide connected topic, so it uses macroeconomic principles of GDP, inflation, and unemployment measures on a vast scale.

The Structure of Market: The Market Structure refers to the features of the market from perspectives of organizational or competitive, which define the nature of competition and the pricing strategy followed in the market. This research topic utilizes macroeconomic principles such as the number of buyers and sellers present in the market.