In merchandising, back to school is the period in which students and their parents purchase school supplies and apparel for the upcoming school year.[1] At many department stores, back to school sales are advertised as a time when school supplies, children's, and young adults' clothing goes on sale. Office supplies have also become an important part of back to school sales, with the rise in prominence of personal computers and related equipment in education; traditional supplies such as paper, pens, pencils and binders will often be marked at steep discounts, often as loss leaders to entice shoppers to buy other items in the store.[2] Many states offer tax-free periods (usually about a week) at which time any school supplies and children's clothing purchased does not have sales tax added.[3]