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Heriot-Watt University, Edinburgh Survival models in modern business Stephen Richards 26 th March 2014 Copyright c Longevitas Ltd. All rights reserved. Electronic versions of related papers and presentations can be found at www.longevitas.co.uk

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Page 1: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

Heriot-Watt University, Edinburgh

Survival models in modern business

Stephen Richards26th March 2014

Copyright c© Longevitas Ltd. All rights reserved. Electronic versions of related papers andpresentations can be found at www.longevitas.co.uk

Page 2: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

Contents1. About the speaker

2. Why care about longevity risk?

3. A spot of time travel

4. Who really owns UK plc?

5. Survival models

6. Actuarial exceptionalism — data

7. Actuarial exceptionalism — models

8. Conclusions

Slide 1 www.longevitas.co.uk

Page 3: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

1. About the speaker

Slide 2 www.longevitas.co.uk

Page 4: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

1. About the speaker

• Graduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD).

• Consultant on longevity risk since 2005.

• Founded longevity-related analytics businesses in 2006:

• Joint venture with Heriot-Watt in 2009:

Slide 3 www.longevitas.co.uk

Page 5: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

2. Why care about longevity risk?

Slide 4 www.longevitas.co.uk

Page 6: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

2. Why care about longevity risk?

“By providing financial protection against the major 18th- and 19th-century risk of dying too soon, life insurance became the biggest financialindustry of that century [. . .] Providing financial protection against thenew risk of not dying soon enough may well become the next century’smajor and most profitable financial industry.”

Peter Drucker (1999)

Slide 5 www.longevitas.co.uk

Page 7: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

2. Why care about longevity risk?

• Managing longevity risk is a major challenge for the next decades.

• It will play a large role in your career!

Slide 6 www.longevitas.co.uk

Page 8: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

3. A spot of time travel

Slide 7 www.longevitas.co.uk

Page 9: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

3. 1909• First UK state pension paid from age 70.

• Probability of a male aged 20 surviving to 70 was 34.8%.

• Life expectancy for a male aged 70 was 8.0 years.

Source: Richards (2013). Period survival probability and period life expectancy calculated accord-ing to ELT 6 Construction A in King (1909). No allowance for mortality improvements.

Slide 8 www.longevitas.co.uk

Page 10: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

3. 2009• UK state pension paid from age 67 (for the speaker anyway).

• Probability of a male aged 20 surviving to 67 is 83.6%.

• Life expectancy for a male aged 67 is 16.3 years.

Source: Richards (2013). Period survival probability and period life expectancy calculated accord-ing to the Interim Life Table for the UK for 2008–2010. No allowance for mortality improvements.

Slide 9 www.longevitas.co.uk

Page 11: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

3. Pop quiz

Q. What would the state pension age have to be to restore the eight-year life expectancy at retirement of the original Old-Age Pension Actof 1908?

Slide 10 www.longevitas.co.uk

Page 12: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

3. Pop quiz

Q. What would the state pension age have to be to restore the eight-year life expectancy at retirement of the original Old-Age Pension Actof 1908?

A. 80 years.

Source: Richards (2013). Period survival probability and period life expectancy calculated accord-ing to the Interim Life Table for the UK for 2008–2010. No allowance for mortality improvements.

Slide 11 www.longevitas.co.uk

Page 13: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

4. Who owns UK plc?

Slide 12 www.longevitas.co.uk

Page 14: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

4. Who owns UK plc?

• Legally, companies are owned by their shareholders.

• However, are shareholders seeing any profits?

• Some FTSE-100 companies appear to be run primarily to fund theirpension scheme. . .

Slide 13 www.longevitas.co.uk

Page 15: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

4. Who owns UK plc?

Employer Dividendspension paid to

contributions shareholdersCompany (£ millions) (£ millions)

Lloyds Banking Group 667 56BT 2,179 590Royal Bank of Scotland 977 301

Source: Figure are for 2012, sourced from LCP’s “Accounting for pensions 2013” report.

Slide 14 www.longevitas.co.uk

Page 16: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

4. Who owns UK plc?

• This state of affairs was predicted by Peter Drucker (yes, him again).

• He called it “pension-fund socialism” (Drucker, 1976).

• Even large companies can be dwarfed by their pension schemes. . .

Slide 15 www.longevitas.co.uk

Page 17: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

4. Tail wags dog

Liability Market cap. RatioCompany (£ billions) (£ billions) L/M

International Airlines Group 18.52 3.43 540%BT 40.99 17.51 234%BAE Systems 25.16 10.93 230%Royal Bank of Scotland 30.11 19.52 154%RSA Insurance 6.43 4.51 143%Babcock 3.04 2.86 106%

Source: Figure are 2012 pension-scheme liabilities sourced from LCP’s “Accounting for pensions2013” report.

Slide 16 www.longevitas.co.uk

Page 18: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

4. Who owns UK plc?

Sometimes the pension scheme even consumes the company:

“Under the terms of the restructuring [...] the Uniq Pension SchemeTrustee agreed to release the Company from its pension debt in exchangefor a 90.2 per cent. shareholding in the Company and a cash payment tothe Pension Scheme.”

Source: Uniq plc (2011). Uniq plc is now part of Greencore.

Slide 17 www.longevitas.co.uk

Page 19: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

5. Survival models

Slide 18 www.longevitas.co.uk

Page 20: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

5. Survival modelsSimple observational structure as longitudinal study:

xi xi ++ ti

di == 0

X

Xxi xi ++ ti

di == 1

Time observed, ti, is shown in grey, while deaths are marked ×.

Slide 19 www.longevitas.co.uk

Page 21: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

5. Survival models• Time observed, ti, is waiting time (central exposed-to-risk to actuaries).

• di is the event indicator.

• ti and di not independent, so considered as a pair {ti, di}.• Not all lives are dead, so survival times are right-censored.

• Lives enter at age xi > 0, so data is also left-truncated.

Slide 20 www.longevitas.co.uk

Page 22: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

5. Survival models• Survival models are ideal for actuarial work — Richards (2008, 2012).

• A portfolio of risks is like a medical study with continuous recruitment.

• Rapid uptake in survival-modelling techniques in actuarial work.

• Foundation of our main business line!

Slide 21 www.longevitas.co.uk

Page 23: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

5. Mortality model for annuities

Alive Deadµµx++t

Source: Longevitas Ltd.

Slide 22 www.longevitas.co.uk

Page 24: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

5. Persistency model for personal pensions

Active

Dead

Paid−up

Transferred

µµx++ta

µµx++tp

ρρx++t

ππx++t

ττx++ta

ττx++tp

Source: Longevitas Ltd.

Slide 23 www.longevitas.co.uk

Page 25: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

6. Actuarial exceptionalism — data

Slide 24 www.longevitas.co.uk

Page 26: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

6. Actuarial exceptionalism — data

• Actuaries have specific modelling requirements. . .

• . . .which are not always shared with other users of survival models.

• Two main differences lie with data preparation and model structure.

Slide 25 www.longevitas.co.uk

Page 27: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

6. Data preparation for non-actuaries

• Data is usually collected on lives.

• Can often model straight after validation.

Slide 26 www.longevitas.co.uk

Page 28: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

6. Data preparation for actuaries

• Data is policy-oriented.

• People have multiple policies.

• Need to ensure independence assumption.

• Need to find n independent lives behind p dependent policies (p ≥ n).

• Process of deduplication.

More details on deduplication can be found at www.longevitas.co.uk.

Slide 27 www.longevitas.co.uk

Page 29: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

6. Wealth and duplicates

Size band (5% of lives per band)

Ave

rage

pol

icie

s pe

r pe

rson

2 4 6 8 10 12 14 16 18 20

1.0

1.2

1.4

1.6

1.8

● ●● ● ● ● ● ●

●●

Source: Richards and Currie (2009).

Slide 28 www.longevitas.co.uk

Page 30: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

6. Deduplication challenges

Problem: client identifier not always reliable or unique.

Solution: use combination key made up from reliable fields, e.g.

— Date of birth

— Gender

— Surname

— First initial

— Postcode

Slide 29 www.longevitas.co.uk

Page 31: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

6. What’s in a name?Problem: teleserviced data contains mis-spellings of same surname, e.g.

— Ritchie

— Richie

— Richey

Solution: use metaphone encoding of names.

Slide 30 www.longevitas.co.uk

Page 32: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

6. What’s in a name?Problem: metaphone structured for Anglo-Saxon names. What about:

— Muhammed

— Muhammad

— Mohammed?

Solution: use double metaphone encoding of Philips (1990).

Slide 31 www.longevitas.co.uk

Page 33: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

7. Actuarial exceptionalism — models

Slide 32 www.longevitas.co.uk

Page 34: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

7. Lifetime distribution

Age at death

Pro

babi

lity

dens

ity

0 20 40 60 80 100 120

0.00

0.01

0.02

0.03

0.04

0.05 © www.longevitas.co.uk

Source: Longevitas Ltd.

Slide 33 www.longevitas.co.uk

Page 35: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

7. Lifetime distribution

Age at death

Pro

babi

lity

dens

ity

0 20 40 60 80 100 120

0.00

0.01

0.02

0.03

0.04

0.05 © www.longevitas.co.uk

right−censored

Source: Longevitas Ltd.

Slide 34 www.longevitas.co.uk

Page 36: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

7. Lifetime distribution

Age at death

Pro

babi

lity

dens

ity

0 20 40 60 80 100 120

0.00

0.01

0.02

0.03

0.04

0.05 © www.longevitas.co.uk

right−censored

left−truncated

Source: Longevitas Ltd.

Slide 35 www.longevitas.co.uk

Page 37: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

7. Model structure for non-actuaries• Survival models in medical trials usually deal with observation times.

• Left-truncation is a relatively uncommon problem for non-actuaries.

• Standard software has few options for left-truncated data.

Slide 36 www.longevitas.co.uk

Page 38: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

7. Model structure for actuaries• In contrast, policyholders enter well into their adult life.

• Actuarial data is therefore almost always left-truncated.

• Often need purpose-built software for this.

Slide 37 www.longevitas.co.uk

Page 39: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

8. Conclusions

Slide 38 www.longevitas.co.uk

Page 40: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

8. Conclusions• Survival models are a natural fit to life-office or pension-scheme data.

• Portfolios are like medical trials with continuous recruitment.

• Actuarial data has specific requirements not common elsewhere.

• Bespoke software is typically needed for actuarial work.

Slide 39 www.longevitas.co.uk

Page 41: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

References — IDrucker, P. F. 1976 The Unseen Revolution, Harper and Row, ISBN:0-06-011097-X

Drucker, P. F. 1999 Innovate or die, The Economist, September23rd 1999

Lane, Clark and Peacock LLP 2013 Accounting for pensions 2013,

Philips, L. 1990 Hanging on the metaphone, Computer Language,1990, 7 (12), 39–43

Richards, S. J. and Jones, G. L. 2004 Financial aspects of longevityrisk, Staple Inn Actuarial Society, London

Slide 40 www.longevitas.co.uk

Page 42: Survival models in modern businessGraduated twice from Heriot-Watt: 1990 (BSc) and 2012 (PhD). Consultant on longevity risk since 2005. Founded longevity-related analytics businesses

References — IIRichards, S. J. 2008 Applying survival models to pensioner mortalitydata, British Actuarial Journal 14

Richards, S. J. and Currie, I. D. 2009 Assessing longevity risk andannuity pricing with the Lee-Carter model, Faculty of Actuaries SessionalMeeting Paper, February 2009

Richards, S. J. 2012 A handbook of parametric survival models foractuarial use, Scandinavian Actuarial Journal, 2012 (4), pages 233–257.

Richards, S. J., Kaufhold, K. and Rosenbusch, S. 2013 Creat-ing portfolio-specific mortality tables: a case study, European ActuarialJournal, DOI: 10.1007/s13385-013-0076-6.

Uniq plc 2011 Statement of 1st April 2011,

Slide 41 www.longevitas.co.uk