Challenges in determining indicated rates for
territories
-Territory tends to be highly correlated with other rating
variables. As we’ve seen, this can be addressed using
multivariate analysis.
-Territories are often set to be such small areas (e.g., zip
codes) that the data in each territory may have very limited credibility. Addressing this challenge will be the focus of this discussion.
Two steps in territorial ratemaking
2. Determining indicated rates for each territory (preferably using a GLM due to the correlations with other variables)
Two basic spatial smoothing approaches and
advantages of each
Two categories of clustering routines (in territorial
ratemaking)
-Quantile methods: Clusters will have equal numbers of
observations or equal weights.
-Similarity methods: Clusters are based on the closeness of estimated relativities.
Why standard ratemaking is problematic for
determining ILFs
-There is generally less data for higher limits so results can be volatile.
-Analyses can produce results that are impractical to
implement (e.g., a lower price for a higher limit).
Assumptions commonly made in pricing ILFs
-All UW expenses and profit are variable and don’t vary by limit.
-Frequency and severity are independent.
-Frequency is the same for all limits.
Why loss data should be trended and developed for
ILF pricing
Higher limits can experience higher severity trends, and
development can take longer on larger claims.
Limited Average Severity for a continuous
distribution
LAS(H) = xf(x) integrated from 0 to H + H * (f(x) integrated from H to infinity)
What an Expense Constant accounts for
For expense costs that do not vary by size of risk. This is
particularly important for small policies since their expenses may be a large portion of their premium.
Why small Work Comp risks have worse loss
experience than large risks
-Small companies usually have less sophisticated safety
programs.
-Small companies usually don’t have return-to-work
programs for injured workers.
-Small companies are not as impacted by or do not qualify for experience rating, so they have less incentive to prevent or mitigate injuries.
Two issues when properties are not fully insured
How premium rate changes as ITV increases based on
skew of severity distribution
-For right-skewed distributions (small losses are more
likely), the rate per $1k of coverage will decrease at a
decreasing rate as coverage increases.
-For uniform distributions, the rate per $1k of coverage will decrease at a constant rate as coverage increases.
-For left-skewed distributions, the rate per $1k of coverage will decrease at an increasing rate as coverage increases.
Coinsurance apportionment ratio, payment, and
penalty formulas
a = min[ F/cV , 1] I = min[aL, F] e = min[L, F] - I