Between candy, costumes and décor, Americans could spend $15 billion on Halloween this year. And, according to a Harris Poll Online survey of more than 2,000 U.S. adults, conducted on behalf CIT Bank, millennials will be responsible for most of that.

On average, younger people are expected to spend $183 each on candy, costumes, decorations and miscellaneous items. That's compared to $70 for those in Generation X and $23 for baby boomers.