• We are pleased to announce that the winner of our Feedback Prize Draw for the Winter 2024-25 session and winning £150 of gift vouchers is Zhao Liang Tay. Congratulations to Zhao Liang. If you fancy winning £150 worth of gift vouchers (from a major UK store) for the Summer 2025 exam sitting for just a few minutes of your time throughout the session, please see our website at https://www.acted.co.uk/further-info.html?pat=feedback#feedback-prize for more information on how you can make sure your name is included in the draw at the end of the session.
  • Please be advised that the SP1, SP5 and SP7 X1 deadline is the 14th July and not the 17th June as first stated. Please accept out apologies for any confusion caused.

April 2019 CM1B Q3

S

Salma

Member
Hi

can someone please explain the approach taken to construct the table for the dependent rates of death and surrender.

Why isn't this formula being used to calculate (aq) d x & (aq) s x:

eg: (aq) d 45= (0.00124/(0.075+0.00124)) * (1-e^-(0.075+0.00124))

Thanks!
 
The surrender decrement is not continuously active on the population. Instead, policyholders only have the opportunity to surrender at the end of each year. (aq)_x^d is therefore = q_x^d as mortality is the only continuously active decrement over a given year of age.

If a policyholder is active at the start of a year of age, x, then they must survive that year in order to surrender at the end of it. So we calculate (aq)_x^s = (1 - q_x^d) * P(surrender at end of year).

Note also that if each decrement was active over the year, then you'd need to use forces of decrement (mu_x^d and mu_x^s) in the formula you've suggested, rather than the q_x probabilities. CM1B September 2019 Q1 (ii) tests this knowledge, so it's a good one to take a look at!
 
Back
Top