Quarters In My Change Jar

Feasibility

To evaluate the feasibility of an upcoming project, I needed to know the approximate distribution of quarters in circulation in the local area. Upon filling my change jar, I filtered out the quarters and counted them. There were 102 quarters.

Trial was repeated 5 days later with 400 quarters from a local bank, then another 400 quarters and results were summed.

By Year

102 Quarters	502 Quarters	901 Quarters

By year the data is a little hard to digest.

By Decade

102 Quarters	502 Quarters	901 Quarters

By binning the data into a point per decade we can get a clearer picture. I think there are a few possible effects here, but the data is so noisy I wouldn't claim anything:

• Attrition - coins are removed from circulation by loss and damage.
• Inflation - according to cointrackers.com, in 1970 there were 556,393,000 quarters produced. But in 1980 there were 1,157,713,000 quarters produced. Though, this trend is also quite noisy.
• Silver harvesting - 1964 and older quarters are made from 90% silver. This means they are highly likely to be removed from circulation

Other work

Rhett Allain at wired has a similar piece up.