BerquistSherman

class chainladder.BerquistSherman(paid_amount=None, incurred_amount=None, reported_count=None, closed_count=None, trend=0.0, reported_count_estimator=None)

Class to alter the inner diagonals of a Triangle using the methods described by Berquist and Sherman.

Parameters:

paid_amount: str

The triangle column associated with paid amounts

incurred_amount: str

The triangle column associated with incurred amounts

reported_count: str

The triangle column associated with reported claim count

closed_count: str

The triangle column associated with closed claim counts

trend: float (default=0.0)

Trend rate underlying average open case reserves.

reported_count_estimator: Estimator

An IBNR estimator for reported_count used to calculate closed_count disposal rates. Estimator can be a Pipeline. If None selected then basic Chainladder model is used.

Attributes:

adjusted_triangle_: Triangle

A set of triangles represented by each simulation

disposal_rate_: Triangle

The disposal rates of closed claims based on the reported_count_estimator

a_: Triangle

Two-period Exponential intercept parameters

b_: Triangle

Two-period Exponential slope parameters

fit(X, y=None, sample_weight=None)

set_params(**params)

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:

**paramsdict

Estimator parameters.

Returns:

selfestimator instance

Estimator instance.

transform(X)

If X and self are of different shapes, align self to X, else return self.

Parameters:

X: Triangle

The triangle to be transformed

Returns:

X_new: New triangle with transformed attributes.

Inherited Methods

BerquistSherman.fit_transform	Fit to data, then transform it.
BerquistSherman.get_metadata_routing	Get metadata routing of this object.
BerquistSherman.get_params	Get parameters for this estimator.
BerquistSherman.set_output	Set output container.
BerquistSherman.to_json	Serializes triangle object to json format
BerquistSherman.to_pickle	Serializes triangle object to pickle.