When a law firm invites its contacts to to take a survey, those people who accept probably form an irregular group in terms of the distribution of their corporate revenue. Their revenue can range by the happenstance of self-selection and how the list was compiled from negligible revenue to many billions of dollars. When the firm’s report describes the revenue characteristics of the group, the firm must decide what ranges of revenue to use.
The firm might slice the revenue categories to put in them roughly equal numbers of participants. Doing this usually means that the largest category spans a wide range of revenue — “$3 billion and up” — whereas the smallest category tends to be narrow — “$0 to 100 million.” Such an imbalance of ranges results from the real-world distribution of companies by revenue: lots and lots of smaller companies and a scattering of huge ones (the distribution is long-tailed to the right). Stated differently, the corporate revenue pyramid displays a very, very broad base.
Alternatively, a law firm might choose to set the revenue ranges by some specific range values, perhaps “\$0-1 billion, \$1-2 billion, \$2-3 billion” and so on. The categories may make sense a priori, but binning revenue this way can result in very uneven numbers of participants in one or more of the categories depending on what categories are chosen, how narrow they are, and the vagaries of who responds.
Davies Ward Barometer (2010) [pg. 10] explained the corporate revenue ranges of its respondents in words. These are unusual ranges. The distribution skews toward remarkably small companies. Note from the last bullet that almost one out of three survey respondents “are not sure of their organization’s annual revenue.” Perhaps they do not want to disclose that revenue, as they work for a privately-held company. Or perhaps the organization has no “revenue,” but has a budget allocation as a government agency.
With a third approach, a firm fits its revenue categories to its available data set so that plots look attractive. You can guess when a firm selects its revenue categories to fit its data set. Consider the plot below from DLA Piper’s compliance survey (2017) [pg. 26]. The largest companies in the first category reported less than $10 million in revenue; the next category included firms with up to 10 times more revenue, but about the same percentage of respondents; the third revenue category again spanned companies with up to ten times more revenue, topping out at $1 billion, but close to the preceding percentages. Then we see a small category with a narrow range of $400 million followed by the two on the right with half the percentages of the left three. It appears that someone tried various revenue categories to find a combination that looks sort of good in a graphic.
The fullest way to describe the revenue attributes for participants turns to a scatter plot. From such a plot, which shows every data point, readers can draw their own conclusions about the distribution of revenue.