How do I link AdSense to each author to see how much revenue each individual author generates? I'm using Wordpress.
Metrics Google Adsense Performance
Depends on how you are placing the AdSense code on the posts.
If you are placing the code within each post, a manual way would be to create a separate AdSense channel for each author and use that code in the posts.
Another way would be to use the author's name in the url of each post (e.g. "example.com/john-doe/article-title"). That way you can aggregate the reports in AdSense by the url and see the revenue each author's post is bringing in.
I found an example with just GA. Create a custom dimension with the author name. Then display the new segment. Then link your Adsense account to your Adwords account. Then you can see adsense per author. (I believe - have not gotten enough data into GA yet.)
You have to scroll down to the bottom of the page.
https://developers.google.com/analytics/devguides/collection/analyticsjs/custom-dims-mets#booya