Social scientists have long noted the lower socioeconomic status of Mainers of French-Canadian ancestry compared with other ethnic groups in the state.

A recent book on global social mobility has shed some light on just how disadvantaged the Americans of French-Canadian descent are — and proposed some different explanations.

U.S. descendants of the original French North American colonists suffer a low rate of social mobility, which is reflected in their under-representation in high-status fields such as law and medicine, and in their lower incomes, education level and wealth.

The book that recently broke this news of the underclass of the descendants of New France in America is “The Son Also Rises: Surnames and the History of Social Mobility,” by Gregory Clark, professor of economics at the University of California-Davis. The scope of Clark’s research is extensive. By looking at surnames to measure social mobility in modern nations, the author found that social mobility is apparently independent of most phenomena — such as taxation, education, revolution — that one would expect to have an impact.

Sweden’s rate of social mobility is not much different from present-day America’s or medieval England’s. This surprising result was garnered by an elegant research method that looked at families, using surnames, over many generations.

A strange discovery made by Clark surprised even him: the persistently low social mobility across the U.S. of those who are descended from “New French” stock. Clark looked at surnames that were more prevalent in Canada than in France and at cases where the great majority of name-holders self-identified as white rather than black. Some of the more common New French surnames in the set identified by the author include Bergeron, Boucher, Cote, Delong, Gagnon, Hebert and Pelletier. New French surnames occur among physicians in the U.S. at a rate three-fifths less than would be expected given their share of the U.S. population. French Canadians are also underrepresented among lawyers.

Another measure of social mobility in any country is the relative representation at elite places of higher learning. From 1940 to 2000 (and even a bit beyond), New France surnames are consistently underrepresented at Ivy League schools, proportionate to their share of the U.S. population, and this trend shows little improvement over decades.

What are the reasons for Franco-Americans’ slow progression upward to the mean? Clark considers whether French Canadians assimilated at a slower rate than, say, Italian- or Irish-Americans (noting that even in 1970, a significant number of people with French Canadian origin, whose parents were both born in the U.S., still spoke French at home). Yet what’s strange, Clark points out, is that even given the relatively high rate of intermarriage between Franco-Americans and other groups, those with surnames from New France remain poorer.

Another theory cited by Clark is that the lower classes of France were overrepresented in the original colonial population that came Canada. And Clark cites evidence that from the 1600s to the 1800s, the lower socioeconomic strata in Quebec was the most fertile. Then, in a possible third round of “negative selection,” the illiterate (possibly those with less social capital) tended to be the migrants to New England, who flocked to work at low-skill factory jobs between 1865 and 1920.

The proposed explanations for the persistent low social mobility of the French Canadians in the U.S. are not meant to demean anyone, nor deny that the children of New France are slowly approaching the average in most measures of social success. Speaking out loudly about the low social mobility of those with the surnames of New France, and possible root causes, is intended to shed light, foster productive discussion and help spur solutions.

Tom Oliver is a Bridgton-based writer who studied sociology at Bridgewater State College, received his MBA in marketing from Suffolk University, and proudly traces a good portion of his ancestry back to hardy settlers of New France.