Since 2010 GDP is growing, unemployment is going down, and real wages have at least remained steady and many analysts claim it has risen. If the economy really was tied to lack of sex we should be seeing a large spike around 2008/2009 and continuing until 2010 or 2011 and then returning to normal rates by 2018.

Granted, there may be some sort of lag between economic changes and the effect on sex lives. E.g. a boyfriend loses a job in 2009, fails to find work in several years, and then gets dumped. But that seems like more of a stretch, and it seems like the pattern of less sex particularly among men is occurring even among people in age cohorts that weren't affected by the economic downturn during the end of the last decade.

Also I think you're referring to the trap of the law of averages incorrectly. The trap of the law of averages is the erroneous notion that because a random even has diverged from the average then the likelihood of it returning to the average is higher. "The coin toss came up head five times in a row, so it'll probably be tails this time" is falling into the trap of the law of averages.