If the social world were ‘flat’ in the sense that it did not matter where you lived or with whom you associated—no place effects, no context effects, no contagion effects—then single-level analysis would do. The message of Subramanian, Jones, Kaddour and Krieger 1 is that the social world usually is not flat, so multilevel analysis usually is called for. The idea that single-level analysis is problematic when there are multilevel effects is quite consistent with Robinson’s classic warning about the ecologic fallacy. 2 In fact, I suspect that Robinson himself would have embraced multilevel analysis had it existed in his day. Because Robinson has had a multiplicity of interpreters, it is sometimes difficult to separate what Robinson actually said from a caricature of what he said (his article is only seven pages long, and I recommend that readers examine it for themselves). In some instances interpreters have ‘out-Robinsoned’ Robinson. To cite one example: after defining terms, Robinson lists, in his third paragraph, more than a dozen pre-1950 articles that used ecological correlations to estimate individual-level correlations. In the next paragraph, referring to ‘these studies’ (sic), Robinson writes that ‘Ecological correlations are used simply because the properties of individuals are not available’ (p. 352). Although that statement refers specifically to the aims of the studies Robinson has just listed, it is sometimes quoted out of context as axiomatic for all social research. To be true to Robinson, let us begin where he did, with the issue of whether individual-level relationships can be reliably inferred from aggregate-level correlations. Consider this simple example from US history: the vote for George Wallace in the 1968 Presidential election. Suppose we want to know how much less likely blacks were (than others) to vote for Wallace, a four-term governor of Alabama and well-known segregationist who ran as a thirdparty candidate. Because we do not have individuallevel election data on who voted for whom, we might try to infer the relationship between race and Wallace vote by calculating the correlation of percent black and percent vote for Wallace across Congressional districts. The correlation, it turns out, is strongly positive (r ¼0.55 for districts in the South 3 ).