double-blind study - an experimental procedure in which neither the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment; a double-blind procedure is used to guard against both experimenter bias and placebo effects.
No they get more expensive, airlines will always advise you to book in advance to take advantage of their best fares. Sometimes they do a special deal but not within a week of flying. I would try another airline or make different plans.
After that, prices climbed as the travel date approached. But too much advance planning isn't good for the bottom line, either. Though, not surprisingly, the highest fares, came with bookings made 11 or fewer days in advance, the next worst timing was 208, 209, and 210 days out, according to the analysis.