Attachment Age Smoothing

import chainladder as cl
import pandas as pd

This simple example demonstrates how a Tail attachment_age can be used to smooth over development patterns within the triangle. Regardless of where the attachment_age is set, the patterns will always extrapolate one year past the highest known lag of the Triangle before applying a terminal tail factor.

raa = cl.load_sample('raa')

results = pd.concat((
    cl.TailCurve().fit(raa).ldf_.T.iloc[:, 0].rename('Unsmoothed'),
    cl.TailCurve(attachment_age=12).fit(raa).ldf_.T.iloc[:, 0].rename('Curve Fit')
), axis=1)

import matplotlib.pyplot as plt
plt.style.use('ggplot')
%config InlineBackend.figure_format = 'retina'

ax = results.plot(title='Exponential Smoothing of LDF');