Insurance companies invest a lot of time and money into optimizing their pricing and accurately estimating the likelihood that customers will make a claim. In many countries insurance it is a legal requirement to have car insurance in order to drive a vehicle on public roads, so the market is very large!
Knowing all of this, On the Road car insurance have requested your services in building a model to predict whether a customer will make a claim on their insurance during the policy period. As they have very little expertise and infrastructure for deploying and monitoring machine learning models, they've asked you to use simple Logistic Regression, identifying the single feature that results in the best performing model, as measured by accuracy.
They have supplied you with their customer data as a csv file called car_insurance.csv
, along with a table detailing the column names and descriptions below.
The dataset
Column | Description |
---|---|
id | Unique client identifier |
age | Client's age:
|
gender | Client's gender:
|
driving_experience | Years the client has been driving:
|
education | Client's level of education:
|
income | Client's income level:
|
credit_score | Client's credit score (between zero and one) |
vehicle_ownership | Client's vehicle ownership status:
|
vehcile_year | Year of vehicle registration:
|
married | Client's marital status:
|
children | Client's number of children |
postal_code | Client's postal code |
annual_mileage | Number of miles driven by the client each year |
vehicle_type | Type of car:
|
speeding_violations | Total number of speeding violations received by the client |
duis | Number of times the client has been caught driving under the influence of alcohol |
past_accidents | Total number of previous accidents the client has been involved in |
outcome | Whether the client made a claim on their car insurance (response variable):
|
# Import required modules
import pandas as pd
import numpy as np
from statsmodels.formula.api import logit
# Read in the data
car_insurance = pd.read_csv('car_insurance.csv')
# print(car_insurance.head())
# print(car_insurance.info())
# print(car_insurance.describe())
# Fill the null value
car_insurance = car_insurance.fillna(car_insurance.mean())
# print(car_insurance.isnull().sum())
# Create a list to store the models
models = []
# Store the features as a variable
df = car_insurance.drop(columns=['id', 'outcome'])
features = df.columns
print(features)
# Modelling with a for loop
for feature in features:
model = logit(formula=f'outcome ~ {feature}', data=car_insurance).fit()
models.append(model)
# Create a list to store model accuracies
accuracies = []
# Loop through the index of the models list
for feature in range(len(models)):
conf_matrix = models[feature].pred_table()
# True negative
tn = conf_matrix[0,0]
# True positives
tp = conf_matrix[1,1]
# False negatives
fn = conf_matrix[0,1]
# False positives
fp = conf_matrix[1,0]
# Calculate accuracy
accuracies.append((tn+tp) / (tn+tp+fn+fp))
# print(accuracies)
# find out the best accuracies
best_accuracy = max(accuracies)
# identify the index with largest score
max_index = accuracies.index(best_accuracy)
# Find out the feature withe largest accuries
best_feature = features[max_index]
# Create best feature dataframe
best_feature_df = pd.DataFrame({"best_feature": best_feature, "best_accuracy": best_accuracy}, index=[0])
print(best_feature_df)