Monte
Carlo Simulation
This powerful statistical simulation tool has a
near-perfect application to the self funded health care plan. A sample Monte Carlo Simulation is
attached. It models the plan and show
these important items of information:
Purposes
What the expected claims
would be if the plan were run without stop-loss of any kind.
Such expected claims are ranged at 67%, 95% and 99.7%
comfort levels.
What
the expected claims would be if the plan were run with specific stop-loss
only. Such expected claims are ranged
at 67%, 95% and 99.7% comfort levels.
What
the expected claims would be if the plan were run with both specific and
aggregate stop-loss. The likelihood of
an aggregate claim is shown.
The
economic value of the specific and aggregate stop-loss and its comparison with
gross stop-loss premiums is by product.
Of
particular utility is the economic value of fine-timing stop-loss terms.
Requisite Data
Usually such simulation is a by-product (exhibit
III) of the Annual Actuarial Report and requires no additional data.
Fees
When used as above, the fees are per simulation by
this sliding scale.
·
First
three simulations $250
·
Next
three simulations 200
·
Over
six simulations 100
Work Product
See Attachment A.
ATTACHMENT
A
MONTE
CARLO SIMULATION – TRADITIONAL FORMAT
HEALTH
CAR PLAN OF THE ABC COMPANY
A. BACKGROUND
Monte Carlo Simulation is a technique of sampling using millions of numbers stored randomly in a computer. A sample of l,000,e.g., would be represented by a series of l,000 of such numbers beginning with the nth number (seed of n, i. e.). Each such number represents a trial similar to the toss of a coin or the throw of a die. Such simulation becomes practical when the underlying probability curve is mathematically represented as with the well-known normal curve, e.g. The probability curve, which represents health care claims, is the lognormal curve; such is similar to the normal curve except the lognormal curve has an extremely long right-tail representative of rare but very large claims.
Actuarial Caveats. Simulation, modeling, sampling, etc., are, at best, an inexact science. The past is not necessarily the best judge of the future. The tragedy of the six-foot person drowning while crossing the river whose average depth measured five-feet must always be kept in mind. Simulation may reinforce, but not replace, common sense. Particularly challenging to the simulator are the numerous characteristics (economic, social, geographic, demographic, e.g.) which may vary by plan and plan year.
B. RELEVANT FACTS OR ASSUMPTIONS
1. Plan Year to which simulation applies is January 1, 1998 to January 1. 1999.
2. Medical plan enrollees assumed to be constant throughout the plan year
a. I 2,630; P/C 778; P/S 316; P + 1 ; F 355; Total 4,079
b. Number
of covered persons is 6,499.
3. Projected paid claims for Plan Year
|
Benefit |
Below Specific |
Above Specific |
Total |
|
Medical |
$10,950,000 |
$250,000 |
$11,200,000 |
|
Dental |
1,250,000 |
0 |
1,250,000 |
|
Rx Card |
2,000,000 |
0 |
2,000,000 |
|
Other |
|
0 |
0 |
|
Total |
$14,200,000 |
$250,000 |
$14,500,000 |
Specific is $150,000
4. 4. Aggregate benefit of $17,569,247 is allocated among:
Medical $13,545,000
Dental $1,546,000
Rx Card $2,478,347
Other _________
Total $17,569,247
5. Number of covered persons filing at least one medical claim 5,199.
6. Simulation
based upon 100 trials is assumed to claim follow the lognormal frequency
distribution. The lognormal is similar
to the normal (bell-shaped) curve except the lognormal has a very right-handed tail.
7. In setting lognormal ,the mean is $2,779 the standard deviation is $10,282
seed number for Monte Carlo purposes is 3.
C. SIMULATION RESULTS
1. 1. Projected plan costs for the Plan Year shown above and set forth as set forth in the COBRA calculation, feasibility study or proposal are as follows:
|
|
a. Actuarially-determined claims above the specific stop-loss attachment point. |
$14,200,000 |
|
|
b. Fixed Costs • Specific Stop-loss • Aggregate Stop-Loss • Administration |
$580,135 29,498 979,292 |
|
|
c. Reserve Maintenance |
514,000 |
|
|
Total |
$16,302,925 |
|
Confidence Percentage |
Minimum |
Maximum |
|
50% |
$14,089,629 |
$14,732,629 |
|
95% |
13,768,129 |
15,054,129 |
|
99.7% |
13,446,629 |
15,685,296 |
3. With the proposed stop-loss attachment point of $150,000 specific-only the expected total claims are $14,148,891 which means that the economic value of such aggregate stop-loss to the plan is $262,238. Total actual claims will be in the ranges (confidence intervals) below indicated:
|
Confidence Percentage |
Minimum |
Maximum |
|
50% |
$13,636,756 |
$14,661,026 |
|
95% |
13,124,621 |
15,173,161 |
|
99.7% |
12,612,486 |
15,685,296 |
D. ACKNOWLEDGMENT
This simulation was prepared by Canton Harker, FSA, MAAA, principal of Self-Funding Actuarial Services, Inc., 8025 North Point Blvd., Suite 207 W. Winston-Salem, NC 27106 at the request of XYZ TPA.