Relation between layer height and bond strength
My3dmatter.com performed a series of tests with PLA, using "a universal testing machine". They conclude:


  Layer height influences the strength of a printed part when it becomes
  thin. A printed part at 0.1mm shows a max stress of only 29MPa, as
  opposed to 35MPa for 0.2mm (21% increase).
  
  Past 0.2mm, the max stress remains fairly constant around 36 MPa (we
  confirmed this conclusion with an extra test at 0.4mm, not shown here
  because it was not part of the same batch).




Note: It is recommended to read the full article to comprehend the complexity of the subject matter.