What do you call the "owner" of an idea?

Solution 1:

to conceive (verb):

Defn. 2 - Form or devise (a plan or idea) in the mind

"the dam project was originally conceived in 1977"

Derived noun forms include conceiver or conceptor

Source: ODO

Solution 2:

"...the effects on those who brought forth these ideas must be examined..."

bring forth
1. To give rise to; produce: plants bringing forth fruit.
2. To give birth to (young).

brought forth. (n.d.) American Heritage® Dictionary of the English Language, Fifth Edition. (2011). Retrieved April 4 2016 from http://www.thefreedictionary.com/brought+forth

Solution 3:

originator (from origin: the point or place where something begins, arises, or is derived)

a person who creates or initiates something. "Wegener was the originator of the theory of continental drift" –Google

"...we must examine the effects these ideas had on their respective originators..."

Here's an Ngram showing conceptor in its non-existence up against originator. Interestingly, only recently has brought forth been surpassed by originator.

As per the title, the "owner" of an IP (intellectual property) is generally referred to as, the holder. However, the average person is more likely to encounter a holder that is using plaintiff as their moniker.