law, data, and lagging indicators

From Fred Rodell's 1939 polemic, Woe Unto You, Lawyers:

"The Law is the killy-loo bird of the sciences. The killy-loo, of course, was the bird that insisted on flying backward because it didn’t care where it was going but was mightily interested in where it had been. And certainly The Law, when it moves at all, does so by flapping clumsily and uncertainly along, with its eye unswervingly glued on what lies behind."

I don't mean to pick on The Law. It's important that laws change somewhat slowly, as an overcompensatory mechanism to counter the madness of popular opinion.

At the same time, however, isn't it strange? The Law itself eventually does end up conforming to changes in popular opinion, though this transition takes much longer than we would like. 

A national consensus often must exist in order for sweeping rulings to occur. There must be "precedent" - ample record of municipal and state courts deciding to rule in a certain direction. Seems like a chicken v. egg situation.

Black folk in America didn't have their rights as US citizens fully protected until the 1960s (though arguably these rights are still not being protected). The LGBTQ community only recently secured their right to marry the love of their life.

I'm sorry, but how can we congratulate our legal system for doing what should have happened long ago? If our society is founded upon the ideal that "all men are created equal," then doesn't it follow that discriminatory rulings shouldn't take centuries to overturn?

Application to "Big Data"

In a broader sense, the Law is very similar to the business world, in which unimaginative decision-makers cower behind data. Most data, just like the Law, is a lagging indicator. What does that mean? That the data points you're looking at to steer your ship describe the past. If you make decisions based on these lagging indicators, you are making the horrible assumption that the future will look, and should look, like the past. (To be fair, in many cases, this is true).

Some data, just like some legal principles and decisions, are leading indicators. They point to what ought to be and what will be. But to discover these leading indicators requires a very deep understanding of (in law) the meaning of unalienable and (in business) the meaning of innovation.