Mergers play important roles in triggering the most active objects in the
universe, including (U)LIRGs and QSOs. However, whether they are also important
for the total stellar mass build-up in galaxies in general is unclear and
controversial. The answer to that question depends on the merger rate and the
average strength of merger induced star formation. In this talk, I will review
studies on spatial density and sSFR enhancement of local mergers found in
NIR/optical selected pair samples. In line with the current literature on
galaxy formation/evolution, special attention will be paid to the dependence of
the local merger rate and of the sSFR enhancement on four fundamental
observables: (1) stellar mass, (2) mass ratio, (3) separation, and (4)
environment.Comment: A review talk; 8 pages; to appear on the Conference Proceedings for
"Galaxy Mergers in an Evolving Universe", held in Hualien, Taiwan (October
2011
