What is the right cost of capital for the various equity issuing options (i.e., US, France, UK, HK)? Measure and explain the cost of capital for each equity option. – How should I do it? what formulas to use and etc

What is the right cost of capital for the various equity issuing options (i.e., US, France, UK, HK)? Measure and explain the cost of capital for each equity option. – How should I do it? what formulas to use and etc