On the ground, Olimar has everything on jiggs. Quick tilts, smashes, and b-up to gimp jigg's aproach.
In the air over the stage, jiggs has roughly 50:50 on olimar. You have a better range there, but he still is hard to WoP.
In the air off the stage, Olimar is screwed. Jiggs has everything on him. He has a horrible recovery, and he has 2 jumps worth of recovery. If you are lucky, you may pikken chain the edge and get your frames before jiggs delivers the final b-air which will leave you out of range.
Ill call this a hard matchup, but there are times when jigglypuff has a huge advantage.
The rest of the time, Olimar has the upper hand. The only problem is getting him off the edge.