FIRE 2.0: Early Retirement in a High-Inflation World

William Bengen's 1994 study in the Journal of Financial Planning, the source of what later became known as the 4% rule, used a 30-year retirement horizon and historical US market data going back to 1926. The follow-on Trinity Study by three Trinity University professors broadly confirmed the result for a 50/50 stock and bond portfolio. Both papers explicitly bounded their conclusions to the historical sample and the 30-year horizon, neither of which fits the typical FIRE retiree, who plans for 40 to 50 years of withdrawals starting in their 40s.

Morningstar's most recent annual safe-withdrawal study, which uses forward-looking capital market assumptions instead of historical bootstrap, has settled in the 3.7% to 4.0% range for a 30-year horizon and lower for longer horizons. The Center for Retirement Research at Boston College has published similar conclusions. The takeaway is not that 4% is wrong, but that the comfort margin around it is narrower than the early FIRE writing suggested.

Where sequence-of-returns risk actually bites

The single biggest threat to a long retirement is the order in which returns arrive, not their average. A retiree who experiences a 30% drawdown in years one and two of withdrawal is in materially more trouble than one who sees the same drawdown in years 28 and 29, even if the long-run geometric mean is identical. The body of research on sequence-of-returns risk — Wade Pfau, Michael Kitces, and Moshe Milevsky have all written extensively on it — converges on a handful of practical mitigations: lower starting withdrawal rates, dynamic spending rules, and a bond or cash buffer big enough to ride out the first major drawdown without selling equities at the trough.

Coast FIRE and Barista FIRE

Two adaptations have become more common as the bar for full FIRE has risen. Coast FIRE describes a saver who front-loads retirement contributions in their 20s and 30s and lets compounding finish the job, working at a lower-stress or lower-income job during the coast period without contributing further. Barista FIRE — the term predates the current Starbucks-pay-and-benefits era — describes a partial retiree who keeps a part-time job specifically to bridge to traditional retirement-account access and, in the US, to keep employer health coverage in place until Medicare eligibility at 65.

Both approaches reduce the dollar target. A household that earns $40,000 in light part-time work needs roughly $1 million less in invested assets to support a $90,000 lifestyle at a 4% withdrawal rate than a household earning nothing. The trade-off is straightforward: time and labour for capital.

“The biggest determinant of retirement income success is not the withdrawal rate; it is the worker's behaviour in down markets.”

Inflation and the dollar target

US headline CPI has averaged around 4.1% annualized over the last five years, well above the Fed's 2% target, and Canadian CPI has tracked a similar path. The Bank of Canada and the Federal Reserve both expect inflation to ease toward target through 2026, but neither projects a clean reversion. For a FIRE saver, the practical implication is that nominal portfolio targets calculated against 2019 expense data understate the real target by 20% to 30% before adjusting for any lifestyle change.

None of this is investment advice. The safe-withdrawal literature is a set of historical and forward-looking estimates, not a guarantee. Households nearing the FIRE crossover point usually benefit from running their numbers through more than one model — a Monte Carlo, a historical bootstrap, and a deterministic constant-return projection — and from being honest about which spending categories are truly flexible. The number that matters is the one that survives all three frameworks.