His research examines the different family structures around the world and their relationship with beliefs, ideologies, political systems, and historical events.

The historian Emmanuel Le Roy Ladurie, who pioneered microhistory, was a friend of the family and gave him his first history book.

[3] He then worked for a time in the literary service of Le Monde daily, then returned to research, working on the hypothesis of a determination of ideologies and religious or political beliefs by familial systems (Explanation of Ideology: Family Structure & Social System, 1983).

In After the Empire: The Breakdown of the American Order (2001), Todd claims that many indices that he has examined (economic, demographic and ideological) show both that the United States has outlived its status as sole superpower, and that much of the rest of the world is becoming "modern" (declining birth rates etc.)

[3] Controversially, he proposes that many US foreign policy moves are designed to mask what he sees as the redundancy of the United States.

In A Convergence of Civilizations: The Transformation of Muslim Societies Around the World (2007), written with fellow demographist Youssef Courbage, Todd criticized Samuel P. Huntington's thesis of a clash of civilizations, pointing instead to indices of a convergence in styles of life and in values among civilisations.

[8] The book aroused copious and emotional hostility, including a critique by the Prime Minister of France, Manuel Valls.

[9] Todd claims to have written quickly, partly out of frustration and not in a purely academic style, though he defends his arguments' basis in his decades of French demographic research.

The book was received negatively in the West, where Todd was accused of being "blinded by ideology", "ignorant on the subject" and relying on Russian propaganda and conspiracy theories;[17][18][19][20] he was, however, praised by Christopher Caldwell on The New York Times.

[22][23][24] Emmanuel Todd criticizes Western policy, as opposed to that of Vladimir Putin, whose propaganda he spreads, notably justifying Russia's invasion of Ukraine by relying on false information originating from Russian disinformation.

[30]There is an implicit but clear reference to The Final Fall published in 1976, and its author, in Robert Littell's book The Company: A Novel of the CIA, a fiction, but with heavy historical inputs, on the American intelligence agency.