The Associated Press HONG KONG (AP) — Shoppers in China have been tightening their purse strings, raising questions over how faltering consumer confidence may affect Saturday's annual Singles’ Day online retail extravaganza. Singles Day, also known as “Double 11,” was popularized by e-commerce giant Alibaba. In the days leading up to the event, sellers on Alibaba and elsewhere often slash prices and offer enticing deals. Given prevailing jitters about jobs and a weak property market, it's unclear how this year's festival will fare. A Bain & Company survey of 3,000 Chinese shoppers found more than three-quarters of those who responded…