Managing the Risk of Variable Annuities: a Decomposition Methodology Presentation to the Q Group. Thomas S. Y. Ho Blessing Mudavanhu.

Transcription

1 Managing the Risk of Variable Annuities: a Decomposition Methodology Presentation to the Q Group Thomas S. Y. Ho Blessing Mudavanhu April 3-6, 2005

2 Introduction: Purpose Variable annuities: new products for household life-cycle consumption Decomposition method: a process to commercialization Significant potential market for asset management

3 Outline Describe variable annuities and their guarantees Valuation of a guarantee and a variable annuity Describe the decomposition methodology Optimal hedging results Implications to investment management

4 Description of the Variable Annuities $1 trillion market Separate account Guarantees Guaranteed minimum account value Guaranteed minimum death benefits Guaranteed minimum withdrawal benefits Guaranteed minimum income benefits

5 Salient Economic Features Fees structure Withdrawal penalty Customer behavior on lapsation Embedded options

6 Describe Guaranteed Minimum Income Benefits: A model No mortality risk, lapsation, Interest rate risk and equity risk Single premium deposit Annuity is a zero coupon bond 10 year bond 15 year accumulation period

7 Describe GMIB: Impact of interest rate risk

8 Payoffs Profile GMIB is an equity put option with stochastic strike price Fees are positively directly related to the strike of the option GMIB as an exchange option Importance of the specification of the interest rate model

9 Valuation of GMIB: Interest rate and equity risk The 2-Factor Ho-Lee (2004) Arbitrage-free 2-factor interest rate model No negative interest rates in valuing annuity No explosive interest rates in modeling equity return Recombining lattice Decouples stock return and bond rates Specify the interest rate distribution consistent with the market prices

10 Two Factor Generalized Ho-Lee Model n P is the price of a T year bond at time n, at state (i, j) i, j( T) (1 + δ ( n k)) (1 + δ ( n k)) P ( T) ( T) ( T) n k 1 k 1 i 1 j 1 n P ( n+ T) 0,1 0,2 n 1 n 1 i, j = δ 1 1 k,1 δ k k k,2 P ( n) k= 1 (1 + δ0,1 ( n k+ T)) (1 + δ0,2 ( n k+ T)) k= 0 k= 0 where and δ δ 1 + δ ( T 1) ( ) = ( 1) 1 + ( T 1) n+ 1 n n n+ 1 i+ 1,1 i,1 T δi,1 δi,1 T n+ 1 δi,1 1 + δ ( T 1) = 1 + ( T 1) n+ 1 n n n+ 1 i+ 1,2 i,2 ( T) δi,2 δi,2 ( T 1) n+ 1 δi,2

11 The one period forward volatilities are defined by and where and δ ( ( m ) 3/2 σ m R ) i R t = exp 2 ( ) min, Δ m i,1 1,1 ( ( ) 3/2 m R R t ) δ (1) = δ = exp 2 σ ( ) min, Δ m m m i,2 i,2 2 i,2 n 1 k 1 i 1 m Pn ( + 1) (1 + δ 0,1 ( n k)) n 1 Ri,1 Δ t = log + log + δ 1 k,1 ( T) k Pn ( ) k= 0 (1 δ 0,1 ( n k T)) + + j= 0 n 1 k 1 i 1 m Pn ( + 1) (1 + δ 0,2 ( n k)) n 1 Ri,2 Δ t = log + log + δ 1 k,2 ( T) k Pn ( ) k= 0 (1 δ 0,2 ( n k T)) + + j= 0

12 Equity Risk Equity risk Lognormal Arbitrage-free relative to the short rate Correlations with interest rate risks ( 2 ) St ( + 1) = St ( )exp rt ( ) 0.5σ + σz

13 Valuation of GMIB: Market Data Equity instantaneous volatility: 20% USD zero swap curve (July 31, 2002) Swaptions Black Vol Swap Tenor (years) Option Term 1yr 2yr 3yr 4yr 5yr 6yr 7yr 8yr 9yr 10yr (years) 1yr yr yr yr yr yr yr

14 Valuation of GMIB: Scenarios 5000 randomly generated interest rate scenarios Equity scenarios constructed from each interest rate scenario The cost of the guarantee max( BT ( ) VT ( ),0)

15 Valuation of VA: Model f is the fee ( eg 300 bpt) P is the single premium e is the expenses ( eg 60 bpt) PV(fees)=(1-(1-f)^n)P VA= ((f-e)/f)pv(fees)-gmib

16 Valuation of VA: Results Fees 0% 1% 2% 3% PV of fees GMIB VA

17 Decomposition Method The need to hedge the guarantees Re-insurance Dynamic hedging Static hedging Quasi-static hedging: the decomposition enables us to build the investment benchmarks

18 Decomposition Method- Description Determine the pathwise values The Arrow-Debreu state-time securities identify the structured product Replicating the pathwise values by benchmark securities Risk neutral probabilities and riskadjusted pathwise value distribution

19 The Procedure Determine the pathwise values of the structured product Specify the hedging instruments Determine the pathwise values of the benchmark securities Determine the optimal hedging (replicating) portfolio

20 GMIB Decomposition Results Hedging instruments: 25 puts and calls Stepwise regression

21 Decomposition of GMIB: No interest rate risk A B C D E Hedging Instrument Strike Dollar Value % Position t-stat Cash Equity Put infinity

22 Decomposition of GMIB A B C D E Hedging Instrument Strike Dollar Value Percentage Position t-statistic Cash Equity Put Equity Put Equity Put Equity Put Bond Call Bond Call Bond Call Bond Call Bond Call

23 Hedging the GMIB 10% Tail Risk A B C D E Hedging Instrument Strike Dollar Value Percentage Position t-statistic Cash Equity Put Equity Put Bond Call Bond Call Bond Call

24 Hedging the GMIB Tail Risk

25 Hedge Stability With Respect to Volatility

26 Applications of the Decomposition Method to Fixed Income Decomposition of a Companion bond FHLMC 1747Q = cash + TSY C(95-18,8.17%) F(95-08,6.45%) F (95-08, 6.87%) Tested on IO, PO, and other CMOs Prepayment risk and the extension risk measured by the caps and floors

27 Applying to the General Account Single premium deferred annuities Embedded option: lapsation related to the rise of interest rates Wallace (1997): implementation of the liability benchmark at Transamerica.

28 Advantages of the Decomposition Clear specification of risks Use as benchmarks for the investment process Managing the tail risk Identify the more complex risks sources: path dependency, inflation

29 Investment Process Investment objectives: Risk and return analysis Determining the tail risk Benchmark construction Portfolio strategy: Determining benchmark Hedging portfolio revision Investment management: Manage against the benchmark Feedback effect Return attribution The role of asset management: evaluate the business process of supplying VA

30 Conclusions: Commercialization Innovations and new product designs as riders to variable annuities Importance of identifying the investment process Price discovery process and completing the market Using the economic indices (eg. Inflation, housing value) as hedging instruments Significant potential market