Paul Romer is the economist who noticed that economic growth kept increasing, and decided to find out why.  His 1990 paper, "Endogenous Technological Change," had an enormous impact.  ('reason' interview here -- very worth reading.) 

Romer's New Growth Theory work rigorously shows that new ideas trigger economic growth.  The 'reason' article summarizes a Romer paper from 2000 called "Should the Government Subsidize Supply or Demand in the Market for Scientists and Engineers?"  (Answer:  the government should subsidize supply.)  Tiny increases in growth rate will raise standards of living for enormous numbers of people, so we should try to do the best we can to encourage economic growth -- that means encouraging new ideas -- that means educating people to be scientists and engineers.  (Note: Romer avoided law school.)

Well, I was already an enormous fan of Paul Romer's.  I've just re-read a wonderful intellectual history of new growth theory by David Warsh that ended with a cheerful description of Romer's departure from standard academic life and entry into the creation of digitized teaching tools for economics students.  Great stuff.  But it gets even better:

Romer has a blog.