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");