GTAP-InVEST User Guide
1. Introduction
This is the User Guide for GTAP-InVEST, a new earth-economy model introduced in “Investing in nature can improve equity and economic returns” (Johnson et al. 2023, PNAS). The content here originally derived from the supplemental information document included with PNAS article. However, development on the model is progressing rapidly, so please refer to this document, which will remain up-to-date. For additional details, please see the GTAP-InVEST Github repository (github.com/jandrewjohnson/gtap_invest). All code and results of the model are available and licensed under a permissive open-source license. Full results may be downloaded at justinandrewjohnson.com/gtap_invest/results.

2. Contents
Narrative chapters
- Model summary — overview of how GTAP, SEALS, and InVEST are coupled.
- Scenarios — scenario design and shock construction.
- GTAP details — economic model formulation and database choices.
- InVEST details — ecosystem service models used downstream of SEALS.
- Ecosystem service impacts — how ES feedbacks enter the second GTAP run.
GTAP Database reference
The current GTAP-Invest pipeline uses the GTAP 12 Data Base (released 2025), aggregated for analysis. Older v11 references are kept for archival comparison.
- GTAP v12 regions (163) — current
- GTAP v12 sectors (65) — current
- GTAP v12 model variables — sets, parameters, value flows, prices, shocks, welfare
- GTAP v11 regions (160) — legacy
- GTAP v11 sectors (65) — legacy
- GTAP v11 model variables — legacy
GTAP-Invest aggregation (v12_s26_r50)
The GTAP-Invest pipeline runs on an aggregated form of the full database — 50 regions and 26 sectors — so simulations are tractable and aligned with the resolution at which SEALS land-use change and InVEST ecosystem services can be coupled to the economic model.
- s26_r50: regions (50) — how 163 v12 regions roll up into 50 r50 regions
- s26_r50: sectors (26) — how 65 v12 sectors roll up into 26 s26 sectors