China shows steep increase in PCT filings

According to information from WIPO, the United States is, and has been, the world's largest international patent application filer, with just under 50,000 applications in 2006, accounting for 34.1 percent of the world's total applications. Following the US were Japan, Germany, the Republic of Korea, France, Britain, the Netherlands and China.

In terms of RATE of change, China was highest. China made a total number of 3,910 international patent applications in 2006, an increase of 56.8 percent compared with the previous year.
The Republic of Korea also saw a sharp rise of its international patent filings in 2006. It filed a total number of 5,935 applications, a rise of 26.6 percent compared with 2005.

Whether with PCT applications (here) or with OECD studies (in the patent grant rate debate, as quoted by Jaffe and Lerner), one must distinguish absolute numbers from rates of change.

From Innovation and Its Discontents:

The OECD calculations indicate that the number of important inventions originating in the United States increased by 51% between 1987 and 1998 . By comparison, the number of successful applications to the USPTO by US inventors increased 105% over the same period. If the examination standards in the United States were not changing, we might expect successful applications in the United States by US inventors to grow at about the same rate as our measure of internationally important inventions originating in the United States . … The fact that the growth in successful PTO applications was, instead, twice as large as the growth of international families is hard to explain in any manner other than declining standards in the US PTO, producing an ever-growing proportion of US patents the patent holders themselves did not think merited patenting elsewhere.