Investigating sine waves in Google Trends
cryptogon.com
cryptogon.com
http://en.wikipedia.org/wiki/Tinnitus#Causes_of_subjective_t...
"Ear infection" has a similar pattern. Although there I'm baffled by the huge spike exactly at Christmas followed by nothing in January.
http://www.google.com/trends?q=ear+infection&ctab=0&...
Tinnitus is sometimes caused by depression. Depression can be seasonal, and there's another vaguely cyclical graph that follows the seasons of the Northern Hemisphere. Spiking in the months after Christmas (bills) and another big one in late spring / early summer (student exams?) and then the onset of winter. There's a big reduction over the summer, and interestingly, a negative spike right at Christmas. Lately, there might be some confounding searches for economic depression -- at least that's how I interpret the latter half of 2008.
http://www.google.com/trends?q=religion,+stress,+depression&...
Notice also the spike in stress and depression searches around Romney's speech on religion, we'll come to that later on.
-
It's even more interesting if you look at it region per region.
* US: http://www.google.com/trends?q=stress,+depression,+religion,...
* UK: http://www.google.com/trends?q=stress,+depression,+religion,...
* Australia: http://www.google.com/trends?q=stress,+depression,+religion,...
There are different patterns in all three regions, but the correlation holds. I took shoulder as a neutral term, to be sure the variations were not related to some global trend in search volume.
-
Surpisingly, though, the Romney speech spike is bigger in worldwide queries than in US specific ones.
At the world scale, the spike is also very correlated with feet, flower and shoulder...
It's not the case in the US... And the Romney spike is much smaller when compared to the average frequency of each term.
* World: http://www.google.com/trends?q=religion,+feet,+flower,+shoul...
* US: http://www.google.com/trends?q=religion,+feet,+flower,+shoul...
Do you have any idea of what happened worldwide in November 2007? Is it a Google bug? Or was there an overall spike in search queries at that point?
At first I thought it was confirming my theory because that's when the housing bubble was really popping. But it was also there for control words, including "the". So I reported a bug in their forum.
But now that's all gone. Either that was speedy corrective action or a transient problem.
The regional differences in seasonal patterns are interresting, I think.
They all exihibit a major drop in the summer months. On top of that there's a 3 month periodicity in Australia and a 1.5 month periodicity in the UK. In the US, there's a drop mid november each year.
Are there English or Australian citizens around to explain what happens? I assume it's related to national holidays, but it would be nice to have a confirmation.
Searches like money, sex and music are quite flat but appear to have a low profile match to this general trend.
"sun cream" and "snowman" are clear counter examples.
Ignore the spike near 14 March and look at the log low dip in summer and the sharp upslope in August-September.
Other very seasonal queries: http://www.google.com/trends?q=mushrooms
Also, for some reason, "DYI", "pi", and "horses" all had large spikes around the end of 2007. Anyone want to guess why? Data gremlins?
http://www.google.com/trends?q=diy%2Cpi http://www.google.com/trends?q=horses%2Cdyi%2Cpi
http://www.google.com/trends?q=natural+logarithm%2Cbase+10%2...
This is a US specific plot, but the world wide one is similar. There are plausible explainations for a correlation between the type of breakfast and the school cycle.
The spike at the end of 2007 appears for any queries when you look at the world-wide data.
... and in Australia, both seem to peak in the July time period, as expected. http://www.google.com/insights/search/#q=runny%20nose%2Cring...
Interesting dip come December and then a spurt that more than makes up for it in January. New year, new job?
To test weather-based theories: compare northern hemisphere and southern hemisphere search trends. (Unfortunately, there's not enough search traffic on [ringing ears] in southern-hemisphere english-speaking regions to be sure... though the thin Australia data is vaguely consistent with the idea their highest traffic is mid-year.)