What it means
The core skill is turning uncertain future events into numbers that can be booked today. An actuary combines historic claims data, population statistics and economic assumptions to estimate what a group of policies or pension promises will actually cost over decades.
In general insurance this shows up as pricing and reserving. Pricing sets the premium charged for a policy, while reserving estimates how much the insurer must hold for claims that have happened but have not yet been reported or settled, a figure that directly determines reported profit.
In pensions the work centres on funding. The actuary values the scheme's obligations against its assets using assumptions about life expectancy, salary growth, inflation and investment returns, and a small change in any one of those assumptions can move the deficit by millions.
Assumptions are where the judgement lives, and they are the reason two competent actuaries can reach different answers. Discount rate choices in particular are contested, because a slightly higher assumed return makes a pension deficit shrink without anything changing in the real world.
The profession has spread well beyond its traditional homes. Actuaries now work in banking on credit risk, in healthcare on cost modelling, in climate risk analysis and increasingly in data science roles, wherever long term uncertainty needs to be priced rather than guessed.
In practice
Real-world examples.
Example
A life insurer's actuary revises its mortality assumptions after a review of the last decade of experience. Policyholders are living slightly longer than assumed, which increases annuity reserves by $34,000,000 and reduces reported profit for the year.
Example
A company sponsoring a defined benefit pension scheme receives its triennial actuarial valuation. The deficit has grown from $12,000,000 to $19,000,000, largely because the actuary lowered the assumed discount rate, and the finance director must now negotiate a longer recovery plan.
Example
A health insurer employs actuaries to price a new small business product. They model claim frequency by age band and region, then set premium tiers that keep the expected loss ratio at 72% while remaining competitive.
Think of it
“Actuary is the math expert for risk-calculating probabilities and pricing.
Formula
Calculation
Expected claim cost per policy = probability of a claim x average claim amount
Risk premium = expected claim cost / (1 - expense and profit loading)
A motor insurer studies a group of 50,000 similar drivers. Historic data shows that 4% of them make a claim in a year, and the average claim settles at $6,000, so the expected claim cost per policy is 0.04 x $6,000 = $240.
The insurer needs to cover commission, administration, reinsurance and a profit margin, which together account for 25% of the premium. The premium required is therefore $240 / (1 - 0.25) = $240 / 0.75 = $320 per policy. Across the whole group the insurer collects 50,000 x $320 = $16,000,000 in premiums against expected claims of 50,000 x $240 = $12,000,000, leaving $4,000,000 for expenses and profit.Case study
Seen in the real world.
This case is illustrative and fictional. Brackenmoor Mutual, an invented regional insurer, had grown its commercial property book aggressively for four years and reported healthy profits throughout. Its newly appointed chief actuary re-examined the reserving basis and found that claims were being settled at an average of 18% above the amounts originally reserved.
The pattern had been hidden by growth, because rising premium income from new policies had covered the shortfall on older ones each year. Correcting the reserves required a one off strengthening of $28,000,000, which turned a reported annual profit into a loss and forced the fictional board to pause its dividend.
The uncomfortable conclusion in this illustrative story was that nothing fraudulent had happened. The reserving assumptions had simply been set years earlier and never revisited against actual claims experience, which is precisely the review an actuary is employed to perform.
Watch out
Common mistakes.
- Treating an actuarial valuation as a precise fact rather than an estimate that depends heavily on the assumptions chosen.
- Confusing an actuary with an accountant, when one estimates future uncertain obligations and the other records and reports transactions that have already happened.
- Comparing pension deficits between companies without checking the discount rates used, which can make similar schemes look very different.
Questions
People also ask.
What qualifications does an actuary need?
Actuaries complete a long series of professional examinations alongside several years of supervised work experience before qualifying to sign formal opinions.
Why do pension deficits move so much year to year?
Because they are the difference between two large numbers, so small changes in discount rates, inflation expectations or life expectancy produce large swings in the gap.
Do only insurers and pension schemes employ actuaries?
No, banks, healthcare providers, regulators and consultancies all use actuarial skills wherever long term financial risk needs to be measured and priced.
From the founder's library
Take it further with the book.
Build your financial confidence beyond this definition. Shihan's full-length guide, Accounting Fundamentals, takes the same plain-English approach and turns it into a complete, practical playbook for non-finance managers, business owners and students - with chapter-end quiz answers and presentation slides included.
25% off with code MMHQ25, applied at checkout. Priced in USD - checkout may show the equivalent in your local currency.
View the book and save 25%