Is it true that the percentile bootstrap method should not be used? If so, what alternatives are there for when $F$ isn't necessarily known (i.e., not enough information is available to do a parametric bootstrap)?
Is it true that the percentile bootstrap method should not be used? If so, what alternatives are there for when $F$ isn't necessarily known (i.e., not enough information is available to do a parametric bootstrap)?
Edit: ###Update
Because clarification has been requested, the empirical bootstrap"empirical bootstrap" from these MIT notes refers to the following procedure:
When forming a $100(1-\alpha)$% confidence interval for $\theta$ in the form $\hat{\theta} \pm c \cdot \text{se}$, where $\text{se}$ is the standard error, gather estimates of $\text{se}$ using bootstrapping and use $\text{se}_{\alpha/2}$, $\text{se}_{1-\alpha/2}$, with subscripts denoting percentiles of the bootstrap estimates.
Paraphrased from Section 11.2 of Computer Age Statistical Inference by Efron and Hastie (2016).
The MIT notes linked above do something similar to this, but not exactly: they compute $\delta_1 = (\hat{\theta}^{*}-\hat{\theta})_{\alpha/2}$ and $\delta_2 = (\hat{\theta}^{*}-\hat{\theta})_{1-\alpha/2}$ with $\hat{\theta}^{*}$ the bootstrapped estimates of $\theta$ and $\hat{\theta}$ the full-sample estimate of $\theta$, and the resulting estimated confidence interval would be $[\hat{\theta}-\delta_1, \hat{\theta} - \delta_2]$$[\hat{\theta}-\delta_2, \hat{\theta} - \delta_1]$.
In essence, the main idea is this: empirical bootstrapping estimates an amount proportional to the difference between the point estimate and the actual parameterdifference between the point estimate and the actual parameter, i.e., $\hat{\theta}-\theta$, and uses this difference to come up with the lower and upper CI bounds.
The percentile bootstrap"percentile bootstrap" refers to the following:
To form a $100(1-\alpha)$% confidence interval for $\theta(\mathbf{x})$, let $\hat{\theta}(\mathbf{x})$ be a statistic for $\theta(\mathbf{x})$, resample to compute $\hat{\theta}(\mathbf{x}^{*})$ with $\mathbf{x}^{*}$ a resampling of the same size as $\mathbf{x}$, and use $[\hat{\theta}(\mathbf{x}^{*})_{\alpha/2}, \hat{\theta}(\mathbf{x}^{*})_{1-\alpha/2}]$ as the confidence interval for $\theta(\mathbf{x})$.
Paraphrased from Section 11.2 of Computer Age Statistical Inference by Efron and Hastie (2016).
use $[\hat{\theta}^*_{\alpha/2}, \hat{\theta}^*_{1-\alpha/2}]$ as the confidence interval for $\theta$. In this situation, we use bootstrapping to compute estimates of the parameter of interest and take the percentiles of these estimates for the confidence interval.
Please let me know if anything I wrote above is unclear or incorrectcompute estimates of the parameter of interest and take the percentiles of these estimates for the confidence interval.