When sorting the References list for the Chicago Style in Word 2016 using the Author-Date system, the references list should be sorted alphabetically by author and date, not author and title, as in the Notes and Bibliography system. The Bibliography Style provided by Word 2016 is incorrect and sorts on the basis of Author and Title instead of Author and Date.

This can be fixed by adding the following lines around line 6365 in the %APPDATA%\Microsoft\Bibliography\Style\CHICAGO.XSL file:

<xsl:if test="string-length(b:Year) > 0">
  <xsl:value-of select="b:Year" />

This content should be inserted into the b:SortingString block and should occur after the elements dealing with the Author, and before the elements dealing with the Title.