Problem: Distance values in the output layer of a spatial join are not in map units
When performing a spatial join, the Join Data dialog box states that 'With the closest option, a distance field is added showing how close the polygon is [in map units].'
On examining the output data, the distance field is not in map units.
The Join Data dialog box is incorrect. The distance units are in a unit of measure associated with the target layer's coordinate system.
Solution or Workaround
Use the Metadata tab in ArcCatalog to determine the units of measure.