1998 年度外来講師による関連講義 |
The blockwise bootstrap for time series
Under dependence, the estimation of the standard error of a statistic or
the construction of a confidence interval is more difficult than under
independence. The blockwise bootstrap works by patching randomly selected
blocks of consecutive observations from the original time series to an
artificial bootstrap series. I will review what is known about this method
and point out where its limitations are and what remedies are being
proposed.
Estimation of mutual information
Mutual information (or relative entropy) between lagged variables in a time
series has been suggested as an alternative to autocorrelations since the
former can capture also nonlinear dependencies. I will point out some of
the difficulties which arise when one estimates mutual information from the
data. In particular, I will show that for a histogram type estimator the
error is always of larger order than n^{-1/2} and will discuss whether
additional smoothing can improve the situation.