In thinking about the empirical analysis of social policies, I've thought it sometimes useful to take the actual results of the policies and then look back and think whether the policy still would have been adopted had the architects of the policy known what the results would be. The answer might still be yes, but thinking about the costs and benefits through this lens helps to illuminate the trade-offs without the inherent biases that people seem to have in admitting that they were mistaken in the first place.
For instance, had the architects of Prohibition known the full costs and benefits that resulted from Prohibition, would they have still supported it? Perhaps yes, but surely the full range of unintended consequences of Prohibition were not fully seen at the time, and if they had been it is not obvious that they would have supported it (and of course they actually ended up repealing it). I recall seeing this same analysis of welfare policy prior to welfare reform in the 1990s: had the architects of the Great Society welfare programs known the unintended consequences that would flow from welfare reform, would they have still supported it?
Another one I wonder about is whether had the Federalists been able to anticipate the course of American constitutional history, would they have nonetheless opposed the inclusion of a Bill of Rights in the Constitution (Madison changed his mind, of course)? It is an interesting thought experiment to think about how American history would have been different had the Federalists prevailed and no Bill of Rights would have been added to the Constitution. One suspects, for instance, that the Supreme Court would have spent most of its time enforcing structural constitutional restrictions and enumerated powers rather than individual rights provisions. Whether that would have been better or worse is an interesting question--it certainly would have been different.
In this vein I offer a provocative essay by Mary Eberstadt on birth control and the sexual revolution. She writes about it through the lens of the Papal Encyclical Humanae Vitae, but I'm interested in it here as a non-religious sociological analysis. My guess is that most readers will conclude that the sexual revolution was a net positive for society. Certainly there were major social and widespread individual benefits from the sexual revolution and birth control technology, and one suspects that many of these social benefits were unforeseen at the time as well. Increased personal autonomy, freedom, and social and economic opportunities for women are certainly important benefits of access to birth control that most of us will easily recognize. Nonetheless, while most readers will conclude that the benefits overall outweighed the costs, Eberstadt frames the issue in a way that certainly caused me to think more deeply about the full costs and benefits of these social developments:
Let's begin by meditating upon what might be called the first of the secular ironies now evident: Humanae Vitae's specific predictions about what the world would look like if artificial contraception became widespread. The encyclical warned of four resulting trends: a general lowering of moral standards throughout society; a rise in infidelity; a lessening of respect for women by men; and the coercive use of reproductive technologies by governments.
In the years since Humanae Vitae's appearance, numerous distinguished Catholic thinkers have argued, using a variety of evidence, that each of these predictions has been borne out by the social facts.
Speculation on the causes of such broad social trends is difficult, of course. Nonetheless, much of the rest of the article is concerned with laying out the empirical case that each of these four developments have actually come about. And reading the list of predicted effects (even before considering the empirical evidence Eberstadt marshals) it seems accurate to me that these are unintended consequences that have in fact come about as side-effects of access to artificial birth control. As Eberstadt stresses, most of this sociological evidence has been developed by secular scholars.
In the end, Eberstadt can be criticized for failing to fully account for the benefits of the sexual revolution, so it is not clear that Humanae Vitae has been "vindicated" (of course, this is a short magazine piece and most readers will easily be able to recognize the benefits of these developments to weigh them in the balance). Nonetheless, I thought it a fresh way of thinking about one of the major social developments of the Twentieth Century as it causes us to think about some of the costs associated with developments that are generally thought to be socially beneficial.