As the supply chain crisis drags on, some holiday shoppers are doubling down, stockpiling gifts in case their favorite items don't arrive in time.

About 20 percent of shoppers said they plan to order more gifts in case some are delayed or canceled because of global shipping bottlenecks. The figure jumps to 44 percent among millennials, according to a survey published last month by Oracle Retail, an analytics company.A global economy out of sync with the rush of consumer demand from countries that have lifted some pandemic restrictions, like the U.S., has helped create the supply chain crisis heading into the lucrative holiday season.

Retailers have shipped imports early and ordered more supplies to keep shelves stocked for eager shoppers. Imports are at record highs - up by more than 20 percent last month compared to 2019 - but companies are still experiencing longer lead times, which can cause them to order more supplies, further backing up ports, according to a research note published last week by Panjiva, the supply chain research unit of S&P Global Market Intelligence.