Does PolicyEngine handle Person-to-Household summation automatically?

Yes, using 'adds' or 'add()' automatically traverses the entity hierarchy, such as summing Person-level variables up to the Tax Unit, SPM Unit, or Household level.

Why should I avoid manual summing with entity.sum()?

Manual summing is an anti-pattern that circumvents PolicyEngine's optimized aggregation engine and makes the code more difficult to read and maintain.

What is the preferred way to count eligible people in a unit?

Set the 'adds' attribute to a list containing the boolean eligibility variable; PolicyEngine will automatically sum the True values as integers across the entity members.

When should I use the 'adds' attribute instead of a formula?

Use 'adds' when a variable is strictly a sum of other variables with no additional logic, as it is cleaner and handles entity aggregation automatically.

PolicyEngine Aggregation Patterns

Name: PolicyEngine Aggregation Patterns
Author: PolicyEngine

byPolicyEngine

•

Data Science & ML

Standardizes variable summation and entity aggregation within the PolicyEngine microsimulation framework.

This skill provides specialized guidance for implementing aggregation patterns in PolicyEngine, focusing on the efficient summing of variables across different entities like households, tax units, and individuals. It helps developers choose between the declarative 'adds' attribute for simple sums and the 'add()' function for complex logic involving conditions or mathematical clips. By automating entity hierarchy traversal, it ensures consistency, improves code readability, and prevents common anti-patterns in tax-benefit model development.

Key Features

01Imperative aggregation with the 'add()' function for complex logic

02Declarative variable summation using the 'adds' class attribute

03Automatic entity hierarchy traversal from individuals to units

04Optimized boolean counting for eligibility and demographic tracking

05Parameter-driven variable lists for maintainable and configurable sums

062 GitHub stars

Use Cases

01Counting the number of eligible members within a family unit based on boolean criteria

02Summing individual income sources to calculate total household or tax unit gross income

03Aggregating a list of specific tax credits defined in parameter files into a single total

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add policyengine/policyengine-claude technical-patterns

For use in Claude.ai and ChatGPT

Download Skill