A unit of size, a one-hundredth of the total. Not to be confused with percentage change. When something increases by 1 percentage point this may be quite different from a 1% increase. For instance, if GDP grew last year by 1% and this year by 2%, the growth rate this year increased by 1 percentage point compared with last year (the difference between 1% and 2%) and also by 100% (2% is double 1%). A 1% increase would mean that the growth rate this year was only 1. 01%.