PolicyEngine Aggregation Patterns FAQs

Name: PolicyEngine Aggregation Patterns
Author: PolicyEngine

Question 1

Does this skill handle person-to-household aggregation?

Accepted Answer

Yes, PolicyEngine's aggregation patterns automatically handle summing values from lower-level entities (like Person) to higher-level entities (like Household or Tax Unit) without manual loops.

Question 2

Can I use parameter lists to define what variables to sum?

Accepted Answer

Absolutely. Both 'adds' and 'add()' support referencing parameter tree paths that contain lists of variable names, making the model more maintainable and configurable.

Question 3

When should I use 'adds' instead of the 'add()' function?

Accepted Answer

Use the 'adds' attribute when a variable is strictly a sum of other variables with no additional logic. Use the 'add()' function inside a formula when you need to apply conditions, limits like max_(), or additional mathematical operations.

Question 4

Why is manual summing considered an anti-pattern in PolicyEngine?

Accepted Answer

Manual summing via entity members is less efficient and more error-prone. Using built-in aggregation patterns ensures that PolicyEngine's internal engine optimizes the calculation and correctly handles entity relationships.

PolicyEngine Aggregation Patterns

Key Features

Use Cases

PolicyEngine Aggregation Patterns

Key Features

Use Cases