The death of law? Computationally personalised norms and the rule of law

The emergent power of big data analytics makes it possible to replace impersonal general legal rules with personalised, particular norms. We consider arguments that such a move would be generally beneficial, replacing crude, general laws with more efficiently targeted ways of meeting public policy goals and satisfying personal preferences. Those proposals pose a radical, new challenge to the rule of law. Data-driven legal personalisation offers some benefits that are worth pursuing, but we argue that the benefits can only legitimately be pursued where doing so is consistent with the agency that the state ought to accord to individuals, and with the agency that the state ought to accord to itself. These two principles –the principle of private agency and the principle of public agency– are prerequisites for the rule of law. Each is incompatible with unrestrained computational personalisation of law.