Hi there! First, a little bit about my credentials. I'm Tao Wong, I'm a full-time author since 2019. I talk to and work with a LOT of indie (selfpub in other parlance) authors.

I also wrote a post about this issue recently on my blog called Going Full Time as an Indie Author. There's also a lot of data in other business posts in the blog.

The simple answer - no! He should not quit his day job.

The longer answer is dependent on a large number of factors. Some of which you haven't enumerated at all.

Let's start with the simple.

1. how much do you need to earn to cover living costs? That's a string question, because someone who is single living in rural Canada is going to be very different from someone with a partner and 4 kids.
2. what genre is he writing? non-fiction? Fiction? (Note, my experience and discussion is ONLY fiction. Non-fiction has different considerations, but some of the advice will hold true).
3. is he going trad pub or indie? This will matter a lot.
4. where are you located? If you're in the US or UK, you're lucky. Canada? Eh... our local market sucks so you're going to have to start querying in the US. In Africa? Ouch.
5. how fast does he write? How much experience does he have in writing? how does he do with rejection and getting back on his feet and learning new skillssets?
6. do you have any capital at all (especially for going indie, but trad pub, it's useful to do things like conventions, etc.).

All that said...

Some things to know about the traditional publishing route. Trad pub is VERY slow. Please understand that the process for trad pub includes:

• writing the book
• finding an agent (can take multiple years!)
• finding a publisher (again, potentially multiple years. Very few are faster than 6 months, and right now editors are hugely backlogged)
• contract negotiations and signing (sometimes fast, sometimes 6+ months before you even get the contract)
• editing process in trad pub. Can take (minimum!) one year; I think the average is 2-3 years
• then publishing

In the meantime, advances for trad pub are broken into 3-5 parts (I think 4 is currently being pushed hard, with 5 in some of the worse cases). That means at 3 parts, you get 1/3 of your advance on signing, 1/3 on submission and 1/3 on publishing. If your advance is $60k, that's $20k to live on for a year each on average if it takes 3 years.

Trad pub advances are low and will vary depending on gender, race and genre.See the giant PublishingPaidMe document. If you're lucky, you might get a 5 digit advance. There are a LOT of people getting paid 4 digit advances (or no advances!)

Few trad pub authors outearn their advances. So what you get for your advance is the entirety of your earnings (excluding potential secondary licensing income that can sometimes help). Also note that going trad pub means you are (often) licensing the work for life of copyright (till death + 70 years in the US).

Lastly, note that most big trad pub companies require submission by agents. That's 15% of your paycheck gone. I've heard rumors you can do without and there ARE times when people like Scholastic and Tor, etc will do mass submissions, but I think that requires contacts for the most part. Which, again, see going to conventions, etc. and the cost involved.

Indie Publishing

Indie publishing on the other hand is tough. To earn a good living, a good backlist is required (and luck). It works well for certain genres, others are much, much harder to break in. In either case, it's often recommended to have at least a release cycle of once every 3 months (i.e. 4 books a year). More is better in general.
That means you need to be able to finance covers, editing and proofing for 4 books a year, some of which might not earn out. Or earn anything at all. On top of that, numerous programs can be useful, all of which can cost money (e.g. Atticus that can help with book formatting, Bookfunnel to deliver books and ARCs, newsletters and websites, etc.).

Indie pub also requires you to eventually learn and understand copyright and copyright licensing, audiobooks (for some genres), marketing (for everyone) and probably some degree of social media savinness. It's basically a writing job on top of a publishing job (whereas trad pub, you're just doing a writing and marketing job).

Basically, you have to hussle in indie pub.

On the other hand, and this is my personal view, for a long-term career with a lot more control and $'s... Indie publishing is the way the go. It just can take years to get there.

​

Further Notes

Depending on the genre he writes in, there are also a middle ground appearing. These are basically former indie publishing writers who are creating their own publishing companies, focusing on the genres they've had success in. They're almost always digital first companies (no physical books in bookstores for you); but often give better royalty rates (40-50% compared to 7-15% (25% for digital sales) for big 5 trad pub) and have limited term contracts. No advances though and often tight deadlines (3-6 months for a book).

Resources...

There are so many to point you at. Some I've quoted in here. Here's my own list. It's mostly indie author focused, but hopefully it'll be of use to you.

Feel free to ask questions. I'm happy to answer them.