As well-born actuaries we all know the long term risks of longevity:
Lots of actuaries keep expending their energy on calculations of 50 years ahead mortality probabilities.... And indeed..., this is challenging....
Some research reports predict a
decline in life expectation,
others and more serious recent reports show a steady increase of life expectation.
Mission Impossible
Fact of actuarial life is that - although long term research is useful and educational - we are no
Actuarial Magicians.
We should never suggest that we're able to value a bunch of complex and systemic risks (liabilities, assets,mortality, costs, demographics, etc) into a reliable consistent model that predicts reality.
It's a farce!
What CAN we do?
Instead trying to compress a complex of long term risky cash flows into one representing unique value, we need to:
- Analyze and model the short term risks
- Develop a method (system) that enables boards of directors to manage and control their risky cash flows (profit share systems, experience rating, etc.).
Example: Short Term Longevity Risk
As a 2011 report of the
National Research Council clearly shows: The previous 50 years we've seen a 3 months yearly increase of lifespan every calendar year.
Instead of recalculating, checking and pondering this trend, let's take a look at the short term effects of this longevity increase trend.
Effect of 'one year life expectancy' increase
First we take a look at the cost effect of the increase of 'one year of life expectancy' on a single-premium of a (deferred) life annuity (paid-up pensions)...
(
Life table total population: United States, 2003 )
Depending on the discounting interest rate, a one year improvement of longevity for a 65 old person demands a 2,3% to 4,0% increase of the liabilities.
Of course the increase of the liabilities of a portfolio (of a pension fund) depends on the (liability weighted) age distrubution of the corresponding portfolio.
Here's a simple example:
This comes close to the rule of thumb as mentioned by
AEGON:
10% mortality improvement adds one year to life expectancy, and one year of life expectancy adds 4% to the required value of a pension fund’s reserves
Conclusion
From the above presented visual sensitivity analysis we may conclude that for general (distributed) portfolio's a 'one year lifetime increase' will demand approximately 4-5% of the actual liabilities.
A three to four months yearly longevity-increase - as is still the actual trend - will therefore demand roughly a substantial 1,5% (yearly) of the liabilities.
This implies that in case your contribution is calculated at 4% and your average portfolio return is 7%, there's 3% left for financing longevity and indexation (=method). As 'longevity growth' in the near future will probably cost about 1,5%, there's only 1,5% left for indexation on the long run.
Case closed
Related links:
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Spreadsheet (xls) with data used in this blog
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Forecasting longevity of Dutch pension scheme members using postcodes
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Increasing life expectancy at pension funds (uvt;2011)
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Life Tables for the United States Social Security Area 1900-2100
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Valuing Pension Fund Liabilities on the Balance Sheet
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No limits to life expectancy?
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Broken Limits to Life Expectancy
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NRC: Explaining divergent levels of longevity (pdf;2011)
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Wolfram Alpha: Longevity U.S.
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AEGON: Longevity Rule of thumb