research guide
Annotated retirement planning research notes
A compact reading guide to withdrawal-rate research, compounding tools, longevity assumptions, and the questions a single FIRE target leaves unanswered.
- Published
- Sources checked
- By
- FIRE Aggregator editorial process
Withdrawal research answers a specific question
A modeled starting withdrawal rate describes a particular portfolio, time horizon, spending rule, and success threshold. Morningstar's 2025 base case reports 3.9% for a 30-year horizon and 90% success under its stated assumptions. That is evidence for one modeled case, not a universal replacement for 4%.
- Record the horizon, asset allocation, confidence threshold, fees, and spending rule beside every rate you compare.
- Dynamic spending methods can raise lifetime spending by accepting year-to-year reductions; decide whether that trade fits fixed expenses.
Longevity and benefit dates change the bridge
SSA's life expectancy tool reports population averages based only on sex and birth date. It explicitly does not incorporate health, lifestyle, or family history. Treat it as a baseline, then test longer lives and a surviving household member.
Social Security full retirement age depends on birth year and reaches 67 for people born in 1960 or later. Claiming choices and benefit estimates belong in the cash-flow timeline rather than being silently excluded from the FIRE number.
A useful review packet
- One current spending ledger with taxes, insurance, irregular replacements, and health costs separated.
- Three return and inflation scenarios, plus an early bear-market scenario.
- Expected Social Security or pension income by claiming date and survivor case.
- A written rule for spending cuts, paid work, or other action if the portfolio falls below a chosen threshold.
Limits
The cited research and government tools use generalized assumptions. They do not account for an individual household's taxes, health, portfolio, benefits, or risk tolerance, and none guarantees that assets will last.
Sources
- Morningstar State of Retirement Income 2025 report
- Social Security Life Expectancy Calculator
- Social Security Retirement Age Calculator
- SEC Investor.gov free financial planning tools
The source-check date records editorial review. Routine builds do not advance it.
Revision history
- — Initial annotated guide published after reviewing the cited primary tools and research report.