Does a new moon effect the bass like a full moon does?

Yes. Both have a positive effect. In the colder months, according to some, the new moon has a more positive effect than a full moon. In the warmer months, the full moon has a more positive effect.

And some say it has no effect at all.

I always seem to catch more and bigger when there is no moon. So I lean toward fishing more when there's a new moon and not a full moon.

I always follow the moon phases to plan trips.
Full moon is equally as good, fish the shadows at night.
Lots of info. out there tracking trophy catches over 50 years showing most are caught within three days before or after one of either moon phases. This has helped me catch trophy fish for many years............I Believe!!!