| Core Technology |
Python (Pandas, Pydantic) |
Python (Core framework) |
Python (built on OpenFisca) |
| Primary Focus |
New Zealand tax and transfer system |
General-purpose microsimulation framework |
Policy analysis for specific countries (UK, US) |
| Country Coverage |
New Zealand only |
Multi-country (France, Spain, etc.) |
UK and US |
| Rule Definition |
JSON files for parameters (with historical fallback), Python for logic |
Python-based Domain Specific Language (DSL) |
YAML for policy rules |
| Extensibility |
Modular pipeline, but self-contained |
Highly extensible framework for adding new countries/rules |
Highly extensible, inherits from OpenFisca |
| User Interface |
None (command-line/library) |
None (provides API for UIs) |
Web-based graphical user interface |
| API |
Python library interface |
REST API |
REST API |
| Data Input |
Python scripts, CSV files, includes syspop synthetic population generator |
JSON via API |
Web UI, JSON via API |
| Community |
Single project |
Open-source community with multiple contributors |
Open-source community with multiple contributors |
| Dynamic Simulation |
Sequential static model with hooks for behavioural responses |
Not a core feature |
Not a core feature |
| Sensitivity Analysis |
Built-in (including EVPI) |
Not a core feature |
Core feature with web UI integration |