Doubling Season and PWs

[Gorzo]

So, since loyalty is tracked in counters, and effects like proliferate and other counter increasing/decreasing effects work with loyalty counters, I am assuming that the second clause of {Doubling Season} works with them as well. Meaning that a planeswalker's "+1" ability would really add 2 loyalty counters. And if a planeswalker has a +4 like {Karn, Liberated}, it effectively becomes a +8 with Doubling Season on the field. Correct?

With that in mind, does a planeswalker entering the battlefield have his starting loyalty doubled? Say you cast {Ajani, Caller of the Pride}. Would he enter with 4, double to 8, and allow me to crash him immediately for cat-a-palooza on the turn that I dropped him? Or since doubling season says "if an effect would place" counters does starting loyalty not count, as casting the planeswalker wasn't really an effect?  And for that matter, is using a +1 qualifying for an effect in the first place, making doubling season not interact naturally with pws at all?

[Keyeto]

As BJ stated in another topic about this, doubling season will double what they come into play with, but adding loyalty counter counts as a cost, not an effect. Thus, they would gain their normal amount.

[Ghebert]

If you proliferate and have a counter put on a planeswalker then it will get double. Planeswalkers have activated abilities. They are not effects.

[Fenster]

If you proliferate and have a counter put on a planeswalker then it will get double. Planeswalkers have activated abilities. They are not effects.

Abilities causes effects. But the effects doesnt add the counters, the cost for the ability does.