It used to be that, when an academic found something new in her or his research, she or he would write a paper and submit it to an academic journal. And it used to be that when corporate research and development departments (or some geezer in a garage) made a discovery, they would rush to apply for a patent.
Now, academics are quite likely to file a patent, or the institution they work for might--or both, in combination. So it would not be surprising to see a growth in patent applications.
The United States Patent and Trademark Office has been issuing patents since 1790. As of March, 2006, the USPTO had issued more than 7 million patents.
And wonder of wonders, miracle of miracles, they have a statistics page that shows patent activity by year since 1790. Wow.
We'll have to juggle a bit here. The applications for patent stops at 2005 (390,733), but the patent grants time series goes to 2006 (173,771). It's kind of important which year to choose, because in 2006 patent grants returned to growth after 2 years of decline. Not coincidentally, the Patent Office hired 1,100 new patent examiners in 2006 to deal with a backlog of applications.
Going to 2006, patent grants have shown a CAGR (compound annual growth rate) of 5.21%, which would cause a doubling of patent grants every 13.65 years. Patent applications started being counted in 1840, and as I said, we don't have 2006 figures. For the 165 years available, patent applications have shown a CAGR of 3.88%, which would double applications every 18.21 years.
Well, perhaps the rate of growth has been higher recently. That's what the five-year comparison is supposed to show. We will focus on patent grants only, and statistics are in the extended post below.
There are only two five year periods where the number of patents granted is double that of the preceding five year period. After the Civil War (1867-1871), when patents climbed from 26,613 to 61,646, and between 1807 and 1811, when patents rocketed from 366 to 898.
There are many five year periods where the numbers of patents declined, the most recent being the period between 1977 and 1981.
The figures below look very much like the real world. As the population increased and the environment became more conducive to technological innovation, human knowledge grew--but not exponentially and not, indeed, in a straight line. Recent performance is good--but no better in percentage terms than many periods preceding it. The number of US patents granted has not doubled in the past 15 years, let alone the past 5. We'll take a look at other countries' patent statistics later--maybe they are making up for the U.S. shortfall.
Click if you want to see the numbers.