Causes of Economic growth: short run and long run

Causes of Long Run Economic Growth:
 - improvement in productivity and efficiency;
 - increase in resources;
 - changes in technology.

Causes of Short Run Economic Growth:

 - Raise in Aggregate Demand due to increase of one of it's components, ceteri paribus.

(http://szwajcarmaciek.blogspot.com/2009/10/economic-growth-short-run-vs-long-run.html)