摘要(英) |
Value-at-risk (VaR) is not only broadly used in portfolio risk measurement but also becomes an important benchmark in risk-management. Moreover, expected shortfall (ES) is a risk measure and has more information about the distribution of returns in the tail. Thus, evaluating precision of VaR and ES is getting more attention. In this paper, we suggest a symmetric GARCH(1,1) model to fit the loss data. Then, we propose an importance sampling technique to reduce the variance and estimate VaR and ES accurately. Besides, we find the method with importance sampling which can get the same precision like other methods but using less sample sizes. In the end, we show the method with importance sampling technique outperforms other methods. |
參考文獻 |
Andreev, A. and A. Kanto (2005). Value-at-risk prediction: A comparison of alternative strategies. Journal of Risk 7 (2), 55-61.
Baillie, R. and T. Bollerslev (1989). The message in daily exchange rates: A conditional variance tale. Journal of Business and Economic Statistics 7, 297-309.
Bollerslev, T. (1986). Generalized autoregressive conditional heteroskedasticity. Journal of Econometrics 31, 307-27.
Bollerslev, T. (1987). A conditionally heteroskedastic time series model for speculative prices and rates of return. Review of Economics and Statistics 69, 542-547.
Cheng-Der Fuh, Inchi Hu, Y.-H. H. and R.-H. Wang (2010). Efficient simulation of value at risk with heavy-tailed risk factors. Operations Research 59 (6), 1395-1406.
Chrisoersen, P. and S. Goncalves (2005). Estimation risk in financial risk management. Journal of Risk 7 (3).
Do, K.-A. and P. Hall (1991). On importance resampling for the bootstrap. Biometrika 78 (1), 161-167.
Engle, R. (1982). Autoregressive conditional heteroskedasticity with estimates of the variance of united kingdom inflation. Econometrica 50, 987-1007.
Fuh, C. and I. Hu (2004). Efficient importance sampling for events of moderate deviations with applications. Biometrika 91 (2), 471-490.
Fuh, C. and I. Hu (2007). Estimation in hidden markov models via efficient importance sampling. Bernoulli 13 (2), 492-13.
Giovanni Barone-Adesi, K. G. and L. Vosper (1999). Var without correlations for nonlinear portfolios. Journal of Futures Markets 19, 583-602.
Hall, P. (1991). Bahadur representations for uniform resampling and importance resampling with applications to asymptotic relative eciency. Annals of Statistics 19,
1062-1072.
Hill, B. (1975). A simple general approach to inference about the tail of a distribution.Annals of Statistics 3, 1163-74.
Hull, J. and A. White (1998). Incorporating volatility updating into the historical simulation method for var. Journal of Risk 1, 5-19.
Kuester, K., S. M. and M. S. Paolella. (2006). Value-at-risk prediction: A comparison of alternative strategies. Journal of Financial Econometrics 4, 53-89.
Mancini, L. and F. Trojani (2011). Robust value at risk prediction. Journal of Financial Econometrics, 1-33.
McNeil, A. J. and R. Frey. (2000). Estimation of tail-related risk measures for heteroscedastic financial time series: An extreme value approach. Journal of Empirical
Finance 7, 271-300.
Nelsen, R. B. (1999). An introduction to copulas.
Paul Glasserman, P. H. and P. Shahabuddin (1999). Asymptotically optimal importance sampling and stratication for pricing path-dependent options. Mathematical
Finance 9, 117-152.
Paul Glasserman, P. H. and P. Shahabuddin (2000). Variance reduction techniques for
estimating value-at-risk. Management Science 46, 1349{1364.
Paul Glasserman, P. H. and P. Shahabuddin (2002). Portfolio value-at-risk with heavy-tailed risk factors. Mathematical Finance 12(3), 239-269.
Pritsker, M. (1997). Towards assessing the magnitude of value-at-risk errors due to errors in the correlation matrix. Financial Engineering News, 14-16.
Shih-Kuei Lin, R.-H. W. and C.-D. Fuh (2006, September). Risk management for linear and non-linear assets: A bootstrap method with importance resampling to evaluate
value-at-risk. Asia-Pacic Financial Markets 13, 261-295. |