The noindex robots meta tag stops the webpage from being indexed in Google etc…, as long as this option is set none of your WordPress Author Archives will be found for relevant searches in any search engines including Google!
Although the noindex robots meta tag doesn’t stop the link benefit (PageRank : PR) from flowing through the Author Archives to the WordPress Posts (Posts will still be indexed and gain link benefit via the Author Archives links), the link benefit spent on indexing the author archives (~15% of the link benefit flowing into the author archives) is wasted!
When noindex is set the ~15% of link benefit that would normally be used to rank the Author Archives for relevant SERPs does nothing, it’s wasted!
The Stallion WordPress SEO Plugin under the Not Index tab there’s a similar Block All Author Archives^^ option that’s highlighted in orange (SEO notice). The Stallion WordPress SEO Not Index feature uses canonical URLs (instead of noindex robots meta tags) to recover most (doesn’t recover it all) of the links benefit that would be wasted from using the Yoast WordPress SEO Noindex Author Archives option.
Continue Reading Yoast WordPress SEO Plugin Noindex Author Archives Tutorial