Transcript Handout 2

Numerical Examples –
Adjustable Features
Jeanne Lee Ying
ACE Tempest Re
Basic Steps
 Build aggregate loss distribution


Lognormal is a common distribution used for aggregate loss
distribution
Model frequency and severity separately
 Usually assume the independence between frequency and
severity
 Apply specific treaty adjustable features to the loss distribution curve
generated or to each simulated year
 Reasonability check
ACE Tempest Re
Numerical Examples
 Profit Commission
 Loss Ratio Corridors
 Loss Ratio Caps
 Swing Rate
ACE Tempest Re
Profit Commission Example
A Casualty Prorata Treaty
 Subject Premium: 50M
 Loss Ratio: 70%

Weighted average based on all year on level loss ratios
 Ceding commission: 22%
 Brokerage: 0%
 Profit Commission: 30% after 15% of reinsurer’s margin
 Profit Commission formula =

0.3 x (premium-loss-expense-reinsurer’s margin)
 What is the expected profit commission for the deal?
ACE Tempest Re
Modeling A Lognormal
Distribution
Model a Lognormal Aggregate Distribution
 Parameters: Loss Ratio (mean): 70%, Standard Deviation (SD): 20%
 CV (Coef. of Varitation)= Standard Deviation / Mean = 0.2 / 0.7 = 0.2857
 Sigma = SQRT (LN((CV^2 +1)) = 0.28
 Mu = LN(mean) – (Sigma^2)/2 = 17.3
 Determine loss ratios with their associated probability
 EXCEL Function Lognormdist (X, Mu, Sigma)
ACE Tempest Re
Profit Commission Example
ACE Tempest Re
Profit Commssion -Key
Observation
 Cost of expected profit commission (1.2%) does not equal to the
cost of profit commission at the expected loss ratio (0%)
 For Casualty lines, historical data may not reflect a full range of
possibilities
 Adjusting CV using judgement to account for more
variability
ACE Tempest Re
Loss Corridor Example
A Casualty Pro Rata Treaty
 Loss Ratio: 70%

Weighted average based on all year on level loss ratios
 Ceding commission: 22%
 Brokerage: 0%
 A Loss Corridor between 80%-90% loss ratio
 What is the expected loss ratio net of the corridor?
ACE Tempest Re
Loss Corridor
ACE Tempest Re
Loss Ratio Cap Example
A Casualty Pro Rata Treaty
 Loss Ratio: 75% with standard deviation of 30%
 Ceding commission: 22%
 Brokerage: 0%
 A Loss Ratio Cap at 110%
 What is the expected loss ratio net of loss ratio cap?
ACE Tempest Re
Loss Ratio Cap
ACE Tempest Re
Modeling Frequency and Severity
Separately
A Casualty Excess of Loss Treaty
 Assume frequency and severity are independent
 Simulate Severity to the Layer
 Simulate on level frequency
ACE Tempest Re
Swing Rated Example
A General Liability Excess of Loss Treaty
 750K xs 250K Layer with 10M Subject Premium
 Premium is adjusted based on 100/80 loading factor subject to a
minimum rate of 10% and a maximum rate of 25%
 Expected burn cost: 18%
 Adjusted Premium= Minimum of


Layer Loss x 100/80 + Minimum Rate x Subject Premium
Maximum Rate x Subject Premium
ACE Tempest Re
Swing Rated Example
A General Liability Excess of Loss Treaty
 For each year, simulate Claim Count Using Poisson. In this case,
Lamda=4.4
 For each claim count, assign a loss severity based on simulation of
Lognormal or Pareto distribution. We used a 5 parameter truncated
Pareto distribution.
 For this example, we simulated 1000 years
ACE Tempest Re
Simulation Summary
# of
Layer
Total
Claim
Loss
Adj Prem
1
1
1
49k
1061k
49k
2
1
176k
1220k
176k
3
0
0k
1000k
4
3
198k
1247k
52k
5
1
393k
1491k
393k
6
6
1156k
2445k
7
2
824k
8
2
Yr
2
3
4
5
6
35k
110k
282k
229k
2k
26k
21k
596k
2030k
664k
160k
1289k
2500k
1003k
286k
-----
-
-
-----
-
-
7
996
2
1239k
2500k
852k
387k
997
7
3029k
2500k
90k
48k
83k
706k
1003k
95k
1003k
998
8
4122k
2500k
1003k
522k
440k
421k
78k
1003k
381k
999
2
399k
1498k
206k
193k
1,000
5
393k
1492k
130k
112k
101k
16k
34k
1772M
2236M
Total
Expected Loss Ratio
8
275k
79%
ACE Tempest Re