Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/17764
Título: | Modelling changes in the unconditional variance of long stock return series |
Autor(es): | Amado, Cristina Teräsvirta, Timo |
Palavras-chave: | Model specification Timevarying unconditional variance Conditional heteroskedasticity Lagrange multiplier test Long financial time series Volatility persistence |
Data: | Fev-2012 |
Editora: | Universidade do Minho. Núcleo de Investigação em Políticas Económicas (NIPE) |
Resumo(s): | In this paper we develop a testing and modelling procedure for describing the long-term volatility movements over very long return series. For the purpose, we assume that volatility is multiplicatively decomposed into a conditional and an unconditional component as in Amado and Ter¨asvirta (2011). The latter component is modelled by incorporating smooth changes so that the unconditional variance is allowed to evolve slowly over time. Statistical inference is used for specifying the parameterization of the time-varying component by applying a sequence of Lagrange multiplier tests. The model building procedure is illustrated with an application to daily returns of the Dow Jones Industrial Average stock index covering a period of more than ninety years. The main conclusions are as follows. First, the LM tests strongly reject the assumption of constancy of the unconditional variance. Second, the results show that the long-memory property in volatility may be explained by ignored changes in the unconditional variance of the long series. Finally, based on a formal statistical test we find evidence of the superiority of volatility forecast accuracy of the new model over the GJR-GARCH model at all horizons for a subset of the long return series. |
Tipo: | Documento de trabalho |
URI: | https://hdl.handle.net/1822/17764 |
Versão da editora: | http://www3.eeg.uminho.pt/economia/nipe/docs/2012/NIPE_WP_2_2012.pdf |
Arbitragem científica: | no |
Acesso: | Acesso aberto |
Aparece nas coleções: | NIPE - Documentos de Trabalho |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
---|---|---|---|---|
NIPE_WP_2_2012.pdf | NIPE WP 02/2012 | 1,74 MB | Adobe PDF | Ver/Abrir |