Tuesday 24 May 2016

Reserving - Part 1 - Incurred vs Paid Claims Chain Ladder

PURPOSE OF RESERVING
1. Delay between claim event and claim settlement date.

2. The ultimate claim cost will only be known after some time.

3. Must set up reserves in respects of those claims to be settled.



ELEMENTS OF RESERVES
1. Known Claims consist of reopened claims reserves, development on known claims & case reserve.

2. Unknown Claims consists of claims in transit and incurred but not reported (IBNR) 

3. IBNR consists late reported claims & development on known Claims (IBNER) 


SHORT TAIL VS LONG TAIL
1. The size of IBNR is largely dependent on the tail(Short Tail Business and Long Tail Business) which depends on speed of claim.


CHAIN LADDER (PAID)
1. Ultimate Claims can be estimated via Paid to Date * Cumulative LDF or Paid to date / %Paid

2. Step 1 - Gather Cumulative Claims Paid by development year 
AY
Development Year

1
2
3
4
2009
6000
10500
13700
13820
2010
7000
12500
16500

2011
8500
15000

2012
10500





3. Step 2 - Compute LDF, Compute Cumulative LDF and % Paid

AY
Development Year

1-2
2-3
3-4
Tail
2009
1.75
1.3
1.01

2010
1.79
1.32


2011
1.76



2012




Average
1.77
1.31
1.01
1
CUM LDF
2.34
1.32
1.01
1
% Paid
43%
76%
99%
100%
Note:
i. Assuming tail factor is 1.00 
ii. LDF1-2 (2010) = 12500/7000 =1.79
iii. CUM LDF 1-2 = 1.75 *1.3*1.01 = 2.34 
iv. Paid 1-2 = 1/2.34 = 43%

4. Compute Projected Ultimate. O/S Liability, IBNR
AY
Paid to Date
Inc To date
Cumulative LDF
Projected Ultimate
O/S Liability
Case Reserve
IBNR
2009
13,820
13,820
1
13,820
-
-
-
2010
16,500
16,600
1.01
16,665
165
100
65
2011
15,000
17,000
1.32
19,800
4,800
2,000
2,800
2012
10,500
13,500
2.34
24,570
14,070
3,000
11,070
TOTAL
55,820
60,920
-
74,855
19,035
5,100
13,935
Note:
i. Projected ultimate Paid to date * CLDF
ii. O/S Liability = Projected Ultimate - Paid to Date
iii. IBNR =  O/S Liability - Case Reserve


CHAIN LADDER (INCURRED)
1. Same process applies to Claims incurred but this time only using incurred data.

AY
Development Year

1
2
3
4
2009
8000
11500
16600
13820
2010
9500
13500
16500

2011
12000
17000

2012
13500





AY
Development Year

1-2
2-3
3-4
Tail
2009
1.44
1.20
1.01

2010
1.42
1.23


2011
1.42



2012




Average
1.43
1.21
1.01
1
CUM LDF
1.75
1.22
1.01
1
% Paid
57%
82%
99%
100%


AY
Paid to Date
Inc To date
Cumulative LDF
Projected Ultimate
O/S Liability
Case Reserve
IBNR
2009
     13,820
     13,820
1
              13,820
-
-
-
2010
     16,500
     16,600
1.01
              16,766
           266
           100
           166
2011
     15,000
     17,000
1.22
              20,740
        5,740
        2,000
        3,740
2012
     10,500
     13,500
1.75
              23,625
     13,125
        3,000
     10,125
TOTAL
     55,820
     60,920
-
              74,951
     19,131
        5,100
     14,031


COMPARISON PL PAID VS INCURRED
1. The IBNR reserve for a portfolio is usually calculated on the basis of both the run-off triangle of paid losses and the run-off triangle of incurred losses.

2. Problem arises when the projection based on paid losses is far different than the projection based on incurred losses.

3. Paid losses may yield a higher ultimate loss projection than incurred losses in one accident year, but in the next accident year, the situation may be entirely reversed, with incurred losses yielding the higher projection of ultimate loss.

4. Suggests further reading on Munich Chain Ladder Method