Although knowledge accumulation is dependent upon relationships among constructs being robust across different measurement and sampling decisions, scholars have not sufficiently established such robustness for the construct of firm growth. Focusing on this construct, we conduct analyses on all Swedish firms incorporated during the 1994 to 1998 period (68,830 firms) and track their growth (or demise) over their first 6 years of existence. Although we typically find low shared variance between different growth measures, there is variability such that some measures demonstrate high and/or moderate concurrent validity. These findings have implications for how we delineate the boundaries of firm growth research and accumulate knowledge—when we are comparing apples with apples and when we are comparing apples with oranges.