The following is from a Ford Foundation study of looting during the 1977 New York blackout. They are in turn summarizing a 1968 article entitled "Looting in Civil Disorders: An Index of Social Change," from _The American Behavioral Scientist_, Vol. 2, No. 4 (March-April 1968) by E. L. Quarantelli and Russell R. Dynes,
The Ford book is by Robert Curvin and Bruce Porter, and has the lurid title of _Blackout Looting!_, but is the usual measured Ford Foundation prose within:
In their studies of the numerous riots in the 1960s, Quarantelli and Dynes
have discovered that looting occurred following the initiation of civil
disturbances. The disturbances as a whole, they found, generally
progressed in three stages.
In the first stage, destruction rather than plunder appears to be the
rioters' intent. It is often initiated by alienated adolescents or
ideologically motivated agitators in a specific area.
In the second stage, there is conscious and deliberate looting, and the
taking of good is organized and systematic. This stage is often dominated
by delinquent gangs and theft groups operating with pragmatic rather than
ideological considerations.
In the third stage there is an open, widespread and nonsystematic taking
of goods. At this point, plundering becomes the normative, the socially
supported thing to do; people from all social and income levels who reside
in the community participate.