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.
Here's why: 1  Cheaper fare classes almost always sell out FIFO leaving the more expensive fares available. 2  Airlines generally do yield management very well, i.e. an airline can often accurately predict elasticity of demand for a given a flight journey, date/time and booking class.