A marginal impact analysis enables you to view the effect that a specific loss results set (the reference portfolio) has on another loss results set. You can also define sub-perils in the Marginal Impact analysis.

For example: An underwriter may want to assess the potential consequences of adding a new contract or portfolio to an existing portfolio. Each marginal impact analysis combines two loss results sets, providing users with two outputs, one for portfolio impact and another for marginal impact.

Touchstone® stores summary EP data (aggregate and occurrence), event totals, and distribution based on the geographic resolution used to save the loss results for both sets of impact results. You can use the portfolio impact results to determine capacity and the marginal impact results to determine pricing.

Inputs to a marginal impact analysis can be detailed loss analysis or loss group results.