Portfolio
Sim
BLOG
WRITING
Blog
Notes on methodology, backtesting, and building the tool.
Why PortfolioSim Uses the GDP Deflator, Not CPI
2026-07-20
Most retirement tools measure inflation with CPI. Here's why I went with the GDP deflator instead — and what difference it makes over a 30-year backtest.
Educational tool — not investment advice ·
Methodology
·
Contact —
[email protected]
← all posts
·
portfoliosim.org