Where does the bootstrap standard error live in the boot class?

They are calculated by print.boot and not stored in the boot object. Look at getAnywhere(print.boot) for the details.

You can either calculate these values yourself or use capture.output.

For your example:

#original:
output$t0
#bias:
mean(output$t)-output$t0
#se: 
sd(output$t)

You can extract the standard errors by using summary:

se <- summary(output)$bootSE

This command seems to work:

apply(output$t,2,sd)[1]

Related