[...] Legislators are beginning to address that by proposing bills that would make long-term unemployment an illicit basis for hiring decisions. But number crunchers may simply feed “length of time since last job” into their hiring models, and if that factor is weighted heavily, it could be utterly decisive. Future legislators need to take into account the ease with which big data mongers can do an end run around law designed for an analog age. For example, in the case of “time since last job,” they may allow it to be up to 15 percent of a “hiring score,” but no more. Just as accounting rules had to adjust to accommodate firms increasingly complex and fractional interests in other firms, laws governing credit and employment decisions need to become far more specific about the extent to which a forbidden ground of decision making can enter into scores meant to influence decisions.