Moz has now published their 2015 search ranking factors, which they claim to the largest study they’ve done yet on this topic.
The study ranks the various search ranking factors based on (a) asking industry experts their thoughts on over 90 factors and (b) using correlation studies to measure the search results and rankings. This year, Moz interviewed 150 leading search marketers who provided expert opinions on over 90 ranking factors. Moz didn’t only use their data for the correlation portion of the study, but they also used data from SimilarWeb, DomainTools, and Ahrefs.
The short version is that links to the domain and page level, including the anchor text, still is the highest factor for Google rankings. The lowest ranking factor is social metrics, TLDs and basic on-page markup, such as href lang and schema.
Here is the infographic of the summary of the results: