ABy Admin
Jul 25'24

Exercise

The exposure is split into three geographic regions: region A, region B and region C. The following accident year 2 data is available:

Region Current Relativity Exposure Weight Ultimate Losses
A 1 40% 645,000
B 1.28 25% 480,000
C 0.5143 35% 285,000

Suppose the following is true:

  • Loss cost inflation is 5% per annum.
  • There are no fixed and variable underwriting expenses.
  • The insurer is targeting a profit percentage of 15% while retaining current rate relativities.

The insurer determines, using the loss ratio method, that rates should be increased by 10% for calendar year 3. Determine the earned premium at current rates during accident year 2 for region B.

ABy Admin
Jul 25'24

The midpoint of the experience period is 07/01/CY2 and the midpoint of the forecast period is the end of calendar year 3; hence, the trend factor equals 1.031.5 = 1.0453, the projected ultimate inflation adjusted losses for accident year 2 equals $1,410,000 and, given a stated rate increase of 10%, the projected loss ratio must equal 0.9353. If the projected loss ratio equals 0.9353, then the aggregate earned premium at current rates equals $1,507,538. The proportion of the aggregate earned premium attributed to region B equals

1.28*0.25/(0.4 + 1.28*0.25 + 0.5143*0.35) = 0.3556

which in turn implies that the earned premium at current rates for region B equals $536,080.5.

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