The first issue is to find how much you need to allocate the membership income to journal income. The sales price of the subscription without membership was $60.00. However, the discount that members received for not receiving the journal was $50.00. If you were once a math person, the answer that you came up with will be one of the following three.
(1) $60.00 x (600 Members with subscription + 300 Subscription only) = $54,000.
(2) ($50.00 x 600 Members with Subscription) + ($60 x 300 Subscription only) = $48,000
(3) (40% x $100 x 600 Members with subscription) + ($60 x 300 Subscription only) = $42,000
These three answers are all correct in a sense. However, we are dealing with this issue in the context of Form 990, which is governed by specific code and rules. To get a correct answer, you should be a good reader of the legal rules too.
The rule can be summarized like so:
- When 20% or more of the total circulation consist of sales to nonmembers, the nonmember price is used to calculate the journal income.
- If the first condition is not applicable and 20% or more members pay reduced due by electing not to receive the journals, the reduction in dues for a member is used to calculate the journal income.
- If neither of these two conditions is applicable, the membership receipt is multiplied by the ratio of periodical cost vs. Sum of periodical cost and other exempt activities cost.
The subscription sale was only 300 out of 900, so it was more than 20% of total subscription sale. Therefore, the first condition was applied, and the subscription price is assumed to be at $60 for all 900 subscription sales.
You should be wary though, as you might get confused with the second condition. More than 40% of members of the Association here have elected not to receive the journal. The second condition, therefore, seems to be satisfied too, right? Or since the first and second conditions are both met, should we not just use the third method or any choice among the three?
Let me get back to the correct reading of the rule. The second rule clearly says that it is applicable “only when” the first condition is not satisfied.  Therefore, when the first condition is met, the second and third rules are not applicable. Therefore, we don’t even have to look into the second and third condition.
If you’ve made it this far, I salute your patience. You are one of few who are not allergic to the complication of legal math. Trust me. Many people are allergic to math. If that’s not the case, they are likely allergic to the laws. If neither is the case, they certainly hate complicated issues.
 26 CFR 1.512(a)-1(f)(4)(i) to (iii).
 See 26 CFR 1.512(a)-1(f)(4)(ii) that the rule reads quite complicated. (Subscription price to nonmembers: If paragraph (f)(4)(i) of this section does not apply and if the membership dues from 20 percent or more of the members of an exempt organization are less than those received from the other members because the former members do not receive the periodical, the amount of the reduction in membership dues for a member not receiving the periodical shall determine the price of the periodical for purposes of allocating membership receipts to the periodical).