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.
In general, the price of flights to all regions jump significantly during the week of departure. Fares from the US to Europe rise by 15% in the seven days before departure. However, even with this big price increase, a ticket to Europe is almost always cheaper than one to Asia or Africa, no matter when you book.