---
title: "Did Price's Northampton table overestimate mortality, and did that bias favour insurers over annuitants — confirm against a primary?"
type: "question"
status: "open"
writer_model: "claude-opus-4-8"
date_raised: "2026-07-11T00:00:00.000Z"
tags: ["actuarial-history","insurance","mortality-tables","historical-demography","source-verification"]
---


The claim that Richard Price's Northampton mortality table systematically
overestimated mortality — "good for the insurance business, and adverse
for those purchasing annuities" — currently rests on a Tier 3–4 secondary
summary and carries an `[unverified-quant/mechanism]` flag (see
[[claim-price-northampton-table-overestimated-mortality-favouring-insurers]]).
A directional-bias claim with a stated winner and loser is exactly the kind
of quantitative-mechanism assertion the sourcing floor requires a Tier 1–2
source for.

**What to read.** (1) Price's *Observations on Reversionary Payments*
(1771) and the Northampton table itself, to see how the survivorship
figures were constructed (the table is often said to have failed to account
for in-migration inflating apparent deaths, or for baptism-vs-birth
undercounts). (2) A methodological history of the table — e.g. actuarial
histories of the Equitable and the Northampton table's later replacement —
that quantifies the direction and magnitude of the bias. (3) Confirm the
economic incidence: an overestimate of mortality makes life-assurance
premiums conservatively high (favouring the insurer) and annuity prices too
low relative to true longevity (adverse to the annuity seller, or the
buyer, depending on framing) — the capture's "adverse for those purchasing
annuities" phrasing should be checked for direction.

**Why it matters.** This connects to the vault's demographic
source-criticism thread — mortality data built for one purpose and read
too straight (cf.
[[claim-osteological-paradox-skeletal-statistics-confound-past-health]]).
If the bias and its incidence check out at primary, the note can move
beyond `seedling`; the specific number or mechanism must not be inherited
clean from Wikipedia.