compared with or compared to
Do the following mean the same?
a net loss of 8 compared with the 1990 result. . .
a net loss of 8 compared to the 1990 result. . .
What difference there may seem to be is probably affected by one’s regional background (American or British) – despite the fact that the major English
dictionaries give separate definitions to the two structures. Webster’s Third (1986) and the Oxford Dictionary (1989) both suggest that compared with is
used when the comparison is part of a broad analysis, and compared to when it’s a matter of specifically likening one thing to another. But the distinction is
probably more honored in the breach than the observance. Webster’s English Usage (1989) found little correlation between the two particles and the two
meanings, and that the two meanings were not necessarily separable anyway. It concluded that any tendency to choose compared to for the meaning “liken” could only be demonstrated for the active verb, not when it was passive or just a past participle. The very similar frequencies of compared to and compared with in data from CCAE also suggest that the two constructions are used indifferently in American English. In British English compared with is a good deal more frequent than compared to: the ratio is about 2:1 in BNC data. Also noteworthy is the fact that compared to appears more often than compared with among spoken data and scripted dialogue. This suggests that it’s the more informal of the two constructions, the one you use when speaking off the cuff, rather than when crafting your prose.
The preference for compared with was once underpinned by the latinist’s insistence that with was the only possible particle, because the prefix in
compare is the Latin cum “with.” Like other Latin-derived principles of usage, its influence has been more pervasive in Britain, and helped to underscore the use of compared with. Yet even there, compared is increasingly construed with to, on the analogy of similar words and structures such as likened to and similar to. The regional preferences for construing compared apply also to the adjective comparable. In British usage comparable to and comparable with are both freely used, appearing in the ratio 4:3 in BNC data. American usage meanwhile is strongly inclined to comparable to, by the evidence of CCAE
Peters- Camridge Guide to English Language
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