Along a separate line of inquiry, the conservative Heritage Foundation continues to press the case that government itself undermines the work ethic. Heritage publishes an annual “Index of Dependence on Government,” which is designed to show that “America is increasingly moving away from a nation of self-reliant individuals, where civil society flourishes, toward a nation of individuals less inclined to practicing self-reliance and personal responsibility.” Heritage adds that “Americans are haunted by the specter of growing mountains of debt that sap the economic and social vitality of the country. The enormous growth in debt is largely driven by dependence-creating government programs.”

At the other end of the political spectrum, Dean Baker, co-director of the Center for Economic and Policy Research, makes a very different case: that our government’s policies have weakened the bargaining position of the working class while enriching the wealthy.

In a series of emails to me, Baker argues that the Federal Reserve’s determination to limit inflation has boosted unemployment, that policies that keep the value of the dollar high hurt employees who face foreign competition, and that trade agreements pit American labor against workers in low-wage developing countries.

Despite the conflicting nature of these left and right analyses, there is a strong case to be made that they are, in fact, complementary and that they reinforce each other. What if we put it together this way? Automation, foreign competition and outsourcing lead to a decline in well-paying manufacturing jobs, which, in turn, leads to higher levels of unemployment and diminished upward mobility, which then leads to fewer marriages, a rise in the proportion of nonmarital births, increased withdrawal from the labor force, impermanent cohabitation and a consequent increase in dependence on government support.

The major roadblock to synthesizing competing explanations has been — and continues to be — political polarization. Vested interests on the left and right have delayed, and in some cases prevented, recognition of the overlap between liberal and conservative hypotheses, and have pointedly ignored evidence that contradicts their preconceived partisan positions.

William Julius Wilson, a sociologist at Harvard and past president of the American Sociological Association, described the disastrous consequences of the hostile reaction on the left to the 1965 “Moynihan Report,” Daniel Patrick Moynihan’s study, “The Negro Family: The Case for National Action”:

“Scholars, particularly liberal scholars, tended to shy away from researching any behavior that could be construed as stigmatizing or unflattering to inner-city minority residents,” Wilson wrote in a 1993 essay. “This left the study of ghetto social dislocations to conservative analysts who, without the benefit of actual research in the inner city, put their own peculiar stamp on the problem, so much that the dominant image of the underclass became one of people with serious character flaws entrenched by a welfare subculture and who have only themselves to blame for their social position in society.”

Wilson has been a key player in challenging liberal scholars to confront issues they had long viewed with trepidation. In his 1987 book, “The Truly Disadvantaged: The Inner City, the Underclass, and Public Policy,” Wilson wrote: “If underclass blacks have limited aspirations or fail to plan for the future, it is not ultimately the product of different cultural norms but the consequence of restricted opportunities, a bleak future, and feelings of resignation from bitter personal experience. Accordingly, behavior described as socially pathological and associated with the ghetto underclass should be analyzed not as cultural aberration but as a symptom of class and racial inequality.”