Any idea why this isn't doing anything? It doesn't error, it just doesn't work.

It is supposed to compare Column A to Column B. IF the cell value in column A is greater than that in Column B, then it should paste Column A into Column C for the same the row. 

Sub Compare_Columns()

Dim Y as integer
Y =1
Do while activecell.value <> empty
Cells (Y,1).select
If activecell.value > Cells(Y,2).value then
cells (Y,1).copy
cells (Y,3).select
activesheet.paste
End if
Y = Y + 1
Loop

End Sub