Why are Jesus' sayings about the poor concentrated in Luke?

I've been researching Jesus' thoughts on poverty and the needy, and I've noticed that Luke's Jesus makes many more pronouncements concerning the poor than the others. What, if anything, do scholars say about this? ***Edit:*** I'm interested in knowing what ___any___ scholar has to say about the preponderance of mentions in Luke. If you know of any scholar who is saying anything about it, please let me know.