Cat ate small piece of yarn

My cat recently (within the hour) ate a piece of soft yarn about 6-7 inches long. He is acting fine and I can not see any yarn in his throat. I am wondering what would be the best option to do. I understand there are risks for this kind of stuff and I know what could possibly happen. I talked to a few vets already and they recommend calling an emergency animal hospital. I did and they said to bring him in to try to induce vomiting since that is the only real thing you can do right now. Obviously they recommend that but, is this necessary or should I just wait it out to see if he poops it out/throws up?

He is a maine coon so he has long hair and gets hairballs a lot. I was wondering if the yarn would have the same effect as his hair since he has hair as long as the piece of yarn. Is it ok to give him food? 

That's a pretty long piece of yarn and the possibilities of it getting tangled up in your cat's intestines would worry me. Especially as he's long haired and I'm thinking it could get caught in a hairball already forming. The good thing about knowing he's done this so recently is that you can try and get it out before it causes harm. I would take him in very soon so they can make him vomit it up.

Yarn and string are really dangerous to cats and kittens, as they can often get caught in the intestines and cause bunching of the intestinal tract. The intestines fold in like an accordion around the string, and the more they tug on it, the more the string cuts into the intestines. This is potentially life-threatening, as it can rupture the intestinal wall and cause sepsis. I'm not trying to scare you, but this is definitely a serious matter and I would take the cat to a vet as soon as possible to get some x-rays if possible. It's always better to be safe than sorry, as problems can arise really quickly with this kind of situation.

Thanks for the info everyone!

Just an update; 24 hours after eating the yarn he passed it in his stool.

My vet and a couple other hospitals reccomended just to keep an eye on him since he was acting totally fine and never tried puking or got off his regular eating schedule. Not to mention that they said after that 2 hour initial period, there isn't much to do besides wait.

He has always seemed like hes had a tough stomach, so I took the chance of shelling out money I don't have to the vet, and it worked out. I'll be a lot more careful about leaving pieces of string around next time! I am very relieved that he passed it.  

Also, to anyone else with this problem: I gave him wet food to get more liquid in his system for it to pass, and also gave him dry food later on that night (I thought more food would speed up/help it pass through.) I also picked up some Richard Organics hairball remedy, which hopefully helped lubrication. I even put a tiny bit of chicken broth in his water so it would entice him to drink more.

Again, thanks for the input guys!