Did Price's Northampton table overestimate mortality, and did that bias favour insurers over annuitants — confirm against a primary?

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.