In what field do researchers focus on investigating the phenomena described above?

Here is the full excerpt of this question: The invisible hand has guided all nations around the world to this prosperity. In what field do researchers focus on investigating the phenomena described above
The answer is :Economics
Invisble hands in this context refers to the power of supply and demand that exist within the market. People who managed to develop a product/services that answer the needs of the market will be most likely to receive the prosperity from the consumers' purchase.

Afederal parliamentary republic is  unlimited.