I found a longer, more complete discussion by Bogle concerning tactical asset allocation. It is in one of his books, "On Common Sense in Mutual Funds." I probably read this in the 2005 era. The section is available in Google Books. Pages 88 through 90 discuss Fine Tuning Your Balance.
https://books.google.com/books?id=a...utual funds tactical asset allocation&f=false
It was unfair of me to post an earlier link to what someone wrote about what Bogle said, instead of beginning with his own words. Reader will have to draw their own conclusion. Even better, one can read the entire book.
My take-away is that a few tactical changes in a lifetime when valuations go insane is a reasonable safety relief from a rigid asset allocation. And this is really a very minor part of Bogle's writings and speeches. I understand market-timing to mean dangerous behavior investors repeat every time there is a correction. So, a large gulf exists between market-timing and changing AA a few times in a lifetime. That is how I see things.
