The common letter-sized paper used in Europe and in most locations outside of North America. At 8.3 x 11.7" (210x297mm), A4 paper is slightly narrower and a little longer than "A" size 8.5 x 11 ...

Typically, a paper check will take three to eight weeks to arrive in ... it creates a digital image of the front of all letter-sized mail. (This excludes magazines, boxes and larger envelopes.) If you ...

This suggests that these data have not been an outsized source of uncertainty in recent years. Read the Economic Letter: Do Low Survey Response Rates Threaten Data Dependence?