| ||Papers published||% share||Impact|
Nations of the Asia Pacific region now produce more physics research papers in the influential international journals indexed by Thomson Reuters than the nations of the European Union. As a group, the Asia Pacific region surpassed the US in physics output a decade ago.
As a percentage of papers in the field of physics, the US has been declining in world share since the mid-1980s, and the EU nations since 2000. The world share of physics papers by Asia Pacific nations is approaching a threefold increase since 1981. China accounts for much of this rise, from just 0.7 per cent of physics output in 1981 to 15.5 per cent in 2007.
An improvement in citation impact, or citations per paper, typically lags an increase in output, and in some cases an increase in output can dampen impact if the additional output is on average of a lower standard. The table above, reporting citation impact relative to the world average in physics (= 1.00), shows that the US scored 56 per cent more than the world average in 2003-07, down from a high of 63 per cent more than the world average in 1986-90. The EU nations stand at 17 per cent more than the world average in 2003-07, the highest yet for the period surveyed here. Asia Pacific nations reached their highest score as well in 2003-07, at 18 per cent under the world average (during this period, relative impact for China has improved from 65 per cent under the world average to 28 per cent under the world average). Latin America, for 2003-07, stands at 15 per cent below the world average in citation impact in physics, and that, too, is its highest score for the period surveyed.
These trends are slow but steady, and they indicate that the “influence gap” between the US and other regions and nations is likely to narrow further in the next decade.