Displaying model statistics (as a sentence) in a view
I'd add a counter cache to Author, i.e. quote_count just to avoid doing the extra query to fetch the number of quotes.

Don't put view concerns (the sentence, in this case) in a model; use I18n/localization instead, especially since you're dealing with pluralization (and right now you're taking the lazy route of saying author(s) and assuming quotes, plural). 

Even if there's only English, the I18n stuff can do some tricks, for instance (in config/locales/en.yml or similar):

en:
  users:
    show:
      your_authors:
        one: "Your author"
        other: "Your authors"
      author_quotes:
        one: "%{name} has %{count} quote"
        other: "%{name} has %{count} quotes"


With that your view can be something like:

&lt;%= t(".your_authors", count: @authors.count) %&gt;
&lt;%= @authors.map { |author| t(".author_quotes", name: author.name, count: author.quotes.size }.to_sentence %&gt;


And #author_statistics can be removed entirely.