Incurred Loss Development Method: Step 3

  1. Establish aging ratios based on known incurred losses for each year of coverage.
  2. Calculate the average ratio for each period
  3. Use average ratio to project ultimate incurred loss on all written insurance. Remaining unknown losses (bold type) in first table are determined using the known losses and the average ratios. Colors show how known losses multiplied by the average ratio determines unknown losses (bold). Remaining unknown losses (black bold type) are detemined in the same way.
Months of Development
Accident Year 12 24 36 48 60 72 84
1984 58,641 74,804 77,323 77,890 80,728 82,280 82,372
1985 63,732 79,512 83,680 85,366 88,152 87,413 87,500
1986 51,799 68,175 69,802 69,694 70,041 70,461 70,531
1987 40,143 67,978 75,144 77,947 79,896 80,375 80,857
1988 55,665 80,296 87,961 89,368 91,602 92,152 92,224
1989 43,401 57,547 61,115 62,093 63,645 64,027 64,091
1990 28,800 39,859 42,330 43,007 44,082 44,346 44,390



Time To Time Ratios
Accident Year 12:24 24:36 36:48 48:60 60:72 72:84 84:Ultimate
1984 1.276 1.034 1.007 1.036 1.019 1.001
1985 1.248 1.052 1.020 1.033 0.992
1986 1.317 1.024 0.998 1.005
1987 1.693 1.105 1.037
1988 1.443 1.095
1989 1.326
1990



Average 1.384 1.062 1.016 1.025 1.006 1.001 1.000

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Copyright © 1996, 1997 Maher Associates, Inc.
Last modified: July 12, 1997