Difference between revisions of "Bornhuetter-Ferguson Formula Proof"

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'''Formulation 1''':
 
'''Formulation 1''':
 
* Ult<sub>r-BF</sub> &nbsp; = &nbsp; z x Ult<sub>r-Dev</sub> + (1 &ndash; z) x Ult<sub>ECR</sub>
 
* Ult<sub>r-BF</sub> &nbsp; = &nbsp; z x Ult<sub>r-Dev</sub> + (1 &ndash; z) x Ult<sub>ECR</sub>
: where z &nbsp; = &nbsp; %reported &nbsp; = &nbsp; 1/CDF
+
: ''where z &nbsp; = &nbsp; %reported &nbsp; = &nbsp; 1/CDF''
  
  
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: = &nbsp; (reported claims) + (1 &ndash; 1/CDF) x Ult<sub>ECR</sub>
 
: = &nbsp; (reported claims) + (1 &ndash; 1/CDF) x Ult<sub>ECR</sub>
  
And the last line is Formulation 2. Since these steps are reversible, we can conclude that Formulation 1 is equivalent to Formulation 2.
+
And the last line is Formulation 2. Since these steps are reversible, we can conclude that Formulation 1 and Formulation 2 are equivalent.

Revision as of 14:04, 3 July 2020

Prove that the following 2 formulations of the reported Bornhuetter-Ferguson method are equivalent:

Formulation 1:

  • Ultr-BF   =   z x Ultr-Dev + (1 – z) x UltECR
where z   =   %reported   =   1/CDF


Formulation 2:

  • Ultr-BF   =   (reported claims) + (1 – 1/CDF) x UltECR

Starting with Formulation 1 and using the fact that Ultr-Dev = (reported claims) x CDF, we have:

  • Ultr-BF
=   z x Ultr-Dev + (1 – z) x UltECR
=   1/CDF x (reported claims) x CDF + (1 – 1/CDF) x UltECR
=   (reported claims) + (1 – 1/CDF) x UltECR

And the last line is Formulation 2. Since these steps are reversible, we can conclude that Formulation 1 and Formulation 2 are equivalent.