In 2003, during my ALM proseminar at the Harvard Extension School, the instructors (Doug and Joe Bond, of Harvard's Weatherhead Center) introduced the class to a fascinating research technique: Counterfactual reasoning.
How does it work? Simply put, using "counterfactuals" to study history or government policy entails applying an alternate reality scenario to a real-world situation. Then, using logic or knowledge of other issues, researchers can evaluate what factors were most important to the real-world situation.
For instance, counterfactual reasoning based on the following scenario allows scholars to evaluate President Kennedy's role in determining U.S. policy in Vietnam in the 1960s:
"Had Kennedy not been assassinated, would the United States have escalated its military involvement in Vietnam in the mid-1960s?"
Authors and scriptwriters have had a field day with counterfactuals, often in the form of "alternate world" fiction, such as Robert Harris' Fatherland (what if Germany had defeated Britain, and Hitler had lived?).
Some strategy-based videogames also incorporate counterfactual scenarios. And it turns out there is academic interest in such games. Wired's Clive Thompson that Harvard historian and counterfactual researcher Niall Ferguson was so fascinated by Making History, "a game where players run World War II scenarios based on exhaustively researched economic realities of the period" that he is helping advise its creator, game studio Muzzy Lane, on a new game series that will let players "model modern, real-world conflicts such as Iraq, Afghanistan and the nuclear confrontation with Iran."
Counterfactual games also tie in with the "Serious Games" movement, as reported by Serious Games Source.