ExcessEPD function

Estimates for excess-loss premiums using EPD estimates

Estimates for excess-loss premiums using EPD estimates

Estimate premiums of excess-loss reinsurance with retention RR and limit LL using EPD estimates.

ExcessEPD(data, gamma, kappa, tau, R, L = Inf, warnings = TRUE, plot = TRUE, add = FALSE, main = "Estimates for premium of excess-loss insurance", ...)

Arguments

  • data: Vector of nn observations.
  • gamma: Vector of n1n-1 estimates for the EVI, obtained from EPD.
  • kappa: Vector of n1n-1 estimates for κ\kappa, obtained from EPD.
  • tau: Vector of n1n-1 estimates for τ\tau, obtained from EPD.
  • R: The retention level of the (re-)insurance.
  • L: The limit of the (re-)insurance, default is Inf.
  • warnings: Logical indicating if warnings are displayed, default is TRUE.
  • plot: Logical indicating if the estimates should be plotted as a function of kk, default is FALSE.
  • add: Logical indicating if the estimates should be added to an existing plot, default is FALSE.
  • main: Title for the plot, default is "Estimates for premium of excess-loss insurance".
  • ...: Additional arguments for the plot function, see plot for more details.

Details

We need that uXnk,nu \ge X_{n-k,n}, the (k+1)(k+1)-th largest observation. If this is not the case, we return NA for the premium. A warning will be issued in that case if warnings=TRUE.

The premium for the excess-loss insurance with retention RR and limit LL is given by

E(min(XR)+,L)=Π(R)Π(R+L) E(\min{(X-R)_+, L}) = \Pi(R) - \Pi(R+L)

where Π(u)=E((Xu)+)=u(1F(z))dz\Pi(u)=E((X-u)_+)=\int_u^{\infty} (1-F(z)) dz is the premium of the excess-loss insurance with retention uu. When L=L=\infty, the premium is equal to Π(R)\Pi(R).

We estimate Π\Pi by

Π^(u)=(k+1)/(n+1)×(Xnk,n)1/γ^×((1κ^/γ^)(1/γ^1)1u11/γ^+κ^/(γ^Xnk,nτ^)(1/γ^τ^1)1u1+τ^1/γ^) \hat{\Pi}(u) = (k+1)/(n+1) \times (X_{n-k,n})^{1/\hat{\gamma}} \times ((1-\hat{\kappa}/\hat{\gamma})(1/\hat{\gamma}-1)^{-1}u^{1-1/\hat{\gamma}} +\hat{\kappa}/(\hat{\gamma}X_{n-k,n}^{\hat{\tau}})(1/\hat{\gamma}-\hat{\tau}-1)^{-1}u^{1+\hat{\tau}-1/\hat{\gamma}})

with γ^,κ^\hat{\gamma}, \hat{\kappa} and τ^\hat{\tau} the estimates for the parameters of the EPD.

See Section 4.6 of Albrecher et al. (2017) for more details.

Returns

A list with following components: - k: Vector of the values of the tail parameter kk.

  • premium: The corresponding estimates for the premium.

  • R: The retention level of the (re-)insurance.

  • L: The limit of the (re-)insurance.

References

Albrecher, H., Beirlant, J. and Teugels, J. (2017). Reinsurance: Actuarial and Statistical Aspects, Wiley, Chichester.

Author(s)

Tom Reynkens

See Also

EPD, ExcessHill, ExcessGPD

Examples

data(secura) # EPD estimator epd <- EPD(secura$size) # Premium of excess-loss insurance with retention R R <- 10^7 ExcessEPD(secura$size, gamma=epd$gamma, kappa=epd$kappa, tau=epd$tau, R=R, ylim=c(0,2*10^4))
  • Maintainer: Tom Reynkens
  • License: GPL (>= 2)
  • Last published: 2024-12-02