1.2 Variable Types

In this section, you learn how to:
  • Describe different types of variables typically encountered in insurance practice
  • Classify a variable into the appropriate category

Before discussing how to use insurance data to make decisions, it is helpful to first describe common data features. People, firms, and other entities that we want to understand are described in a dataset by numerical characteristics. As these characteristics vary by entity, they are commonly known as variables. To manage insurance systems, it will be critical to understand the distribution of each variable and how they are associated with one another. We will encounter datasets that have many variables (“high dimensional”) and so it useful to begin by classifying them into different types. As will be seen, this classification is not strict; there is overlap among the types. Nonetheless, the classification summarized in Table 1.1 and explained in the remainder of this section provide a solid first step in framing a dataset.

Table 1.1. Variable Types
Variable TypeExample
Qualitative
BinarySex
Categorical (Unordered, Nominal) Territory (e.g., state/province) in which an insured resides
Ordered Category (Ordinal)Claimant satisfaction (five point scale ranging from 1=dissatisfied to 5 =satisfied)
Quantitative
Continuous Policyholder's age, weight, income
DiscreteAmount of deductible
CountNumber of insurance claims
Combinations of Discrete and Continuous Policy losses, mixture of 0's (for no loss) and positive claim amount
Interval Variable Driver Age: 16-24 (young), 25-54 (intermediate), 55 and over (senior)
Circular DataTime of day measures of customer arrival \hline
Multivariate Variable
High Dimensional DataCharacteristics of a firm purchasing worker's compensation insurance (location of plants, industry, number of employees, and so on)
Spatial DataLongitude/latitude of the location an insurance hailstorm claim
Missing DataPolicyholder's age (continuous/interval) and ``-99'' for ``not reported,'' that is, missing
Censored and Truncated DataAmount of insurance claims in excess of a deductible
Aggregate ClaimsLosses recorded for each claim in a motor vehicle policy.
Stochastic Process RealizationsThe time and amount of each occurrence of an insured loss

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