correlation of keyword in title
In 2014 they found the correlation was 0.02 – still insignificant.
Ranking Factors 2014
Lastly, it was found to be -0.04 in 2016.
General ranking factors in 2016
As a result, they say, for the last six years, the keyword in the title has not been associated with good rankings.
Ahrefs actually found a good correlation in their 2016 study. The data seemed very biased italy telephone number data so the analyst’s comment was blunt: “But will using an exact match keyword in your page’s title tag make your page rank better? Probably not!”
Finally, a correlation study I did in 2017 found no basis for the keyword in the title being a ranking factor. The data appears to be completely random – as if the keywords in the title make no difference.
The calculated correlation for exact match use of the keyword in the title was 0.003. While allowing the words to be separated increases the correlation to 0.007, this is still horribly insignificant.
To summarize, 5 big reasons why the keyword in the title does not matter:
SearchMetric's studies show that this doesn't matter.
Brian Dean's data suggests that doesn't matter.
SEMRush's data suggests that doesn't matter.
Ahrefs' analyst says it probably doesn't matter.
My data shows it doesn't matter.

When all these indicators are put together, there should be a strong indication that the keyword in the title is not a very important SEO initiative. If it is a ranking factor, the amount of statistical noise and small effects clearly prove that it is at least insignificant.
Yet 99% of SEOs I meet still say the keyword in the title is important.
Moreover, SEO experts often ask me to defend and justify my opinion, which I am happy to do. It seems strange that believing that the keyword in the title does not matter is still a controversial opinion in 2018.
Final Thoughts and Pragmatism
A keyword in the title is a pretty minor thing in the grand scheme of SEO.
How long does it take to produce a great 2,000-word article? Hours of focused work. Compare that to the minute it takes to add the keyword to your title tag.
include the keyword in the title tag
Also, I am not claiming that the relevance of the title tag is unimportant, so if you want to be on the safe side, feel free to include the keyword.
My priority is to write a great title tag that’s click-worthy, and I’d bet my money on CTR affecting rankings much more than the keyword in the title. Of course, these two initiatives aren’t mutually exclusive. Skeptics or perfectionists might target both.
To summarize my argument in one powerful sentence: keywords in the title are probably not a ranking factor and certainly not an important SEO initiative.
Note: I don’t believe I know everything. If you have great evidence about the keyword in the title that isn’t publicly available or that I’ve missed, please leave a comment or let me know on LinkedIn. I’m always open to changing my mind if new evidence comes to light.