  The baseline distribution can be specified diachronically, in terms of some distribution that held at an earlier time. Economists, for example, often refer to policies as having redistributive effects when they engender a different pattern of holdings than obtained previously. Redistribution of wealth, in this sense, occurs whenever there is a shift in patterns of holdings over time (among some set of subjects) in response to some policy or other social mechanism. On this understanding, we can determine whether redistribution has taken place by identifying (1) a pattern of holdings at time t1 that characterizes the initial distribution; (2) a pattern of holdings at time t2 that characterizes the later distribution; and (3) some policy or other social mechanism that, intentionally or not, caused the change in patterns of holdings between t1 and  t2.[2]  Let us call redistribution that invokes a diachronically specified baseline ‘diachronic redistribution.’ Diachronic redistribution can be brought about through many different means, including the reform of social institutions (for example, torts, rules governing competition, trade and tax policy, or the structure of markets in capital and labor), changes in the prevailing social ethos, or specific market or other interventions by governments.