Cummins v. Robbin Required/Risk Adj Rate of Return

What is the difference between:



Cummins Required Rate of Underwriting Return --> -(Liab i) x Risk Free Rate + Betai x (Market Rate - Risk Free Rate)



And



Robbins Risk Adjusted Rate (From Method 6) --> Risk Free Rate + Betai x (Market Rate - Risk Free Rate) ?



Thanks!

Cummins v. Robbin Required/Risk Adj Rate of Return