The strength of the economy and people's opinions about how the economy will fare in the future are two main elements that determine how much money people spend.
The economy is stronger this year than last, but shoppers may still have lingering fear from the recession of 2008-09.
Shopping trends have also changed over the last few years -- with more people buying online. The aging Babyboomers have also caused more to be spent on items that an aging population enjoy.