DecL at a glance

Common DecL clauses. In Python: build('agg Book ...') or an %%agg cell.

Anatomy of an aggregate

agg Booklabelkeyword, then a label you choose
250 claims exposure volume: amount of business
1000 xs 0optional coverage: limit xs deductible
sev lognorm 100 cv 1.5severityseverity curve: family, mean, cv
occurrence net of 250 xs 750occurrence reinsuranceoptional, before frequency
poissonfrequencyclaim count distribution
aggregate net of 5000 xs 30000aggregate reinsuranceoptional, after frequency
note{main book}traileroptional note
hints{bs=1;log2=16;}traileroptional update hints
Portfolio several aggregates, one total
port Two.Books
  agg Book 250 claims 1000 xs 0 sev lognorm 100 cv 1.5 poisson
  agg Casualty 20 claims 2000 xs 0 sev lognorm 250 cv 2 mixed gamma 0.4

Units are independent and share one grid; each may carry its own reinsurance. A unit can come from the library, agg.BasicBook. Pricing allocates the total to the units.

Profit and loss premium, less losses, less expenses
38000 premiumless agg Book ...less 25% premium expense=margin
xpnl Book.PnL
  38000 premium    # or inherit premium or derive premium
  less
    agg Book 250 claims 1000 xs 0 sev lognorm 100 cv 1.5
      occurrence net of 250 xs 250 deposit 3400
                    and 500 xs 500 deposit 1600
      poisson
  less 25% premium expense as "G&A"
       1000 fixed expense as "Overhead"
  peel top-down    # or bottom-up

Alternative forms

Exposure SeverityFrequency Reinsurance
volumecoverage (optional)
250 claims expected count
25000 loss expected loss
40000 premium at 65% lr
1000 exposure at 25 rate units × rate
1000 xs 0 limit xs deductible
omit for unlimited
[500 1000] xs [0 0] a mix
sev lognorm 100 cv 1.5 mean, cv
sev gamma 100 cv 1 any scipy.stats
sev 50 * invgamma 2.5 scale, shape
sev ... ! unconditional
poisson
mixed gamma 0.3 mixing cv 0.3
fixed exactly the count
occurrence net of 75% po 600 xs 400 partial placement
aggregate ceded to 250 xs 250 and 500 xs 500 limit xs attachment, lowest first
aggregate net of 66% po inf xs 0 rate 100% cede 30% 66% quota share w 30% ceding commission
less common
[100 200 50] claims vectorized exposure
dfreq [1 2 3] [.5 .3 .2] listed counts and probabilities (optional, default equally likely)
4000 xs 1000 an excess layer
dsev [1 2 10] [.4 .4 .2] listed
sev 40 * expon + 10 scale and shift
picks [250 1000] [20000 4500] adjust expected loss by layer
negbin 2 variance multiple
binomial 0.5
50% po 500 xs 500 partial placement
tower [0 250 500 1000] program breakpoints
rol 5% deposit 600 reinstatements 1 at 100%