http://ac.els-cdn.com/S0140673600027410/1-s2.0-S0140673600027410-main.pdf?_tid=4d262cf8-00b7-11e5-912d-00000aab0f26&acdnat=1432322477_abd00ba83d30dd75463967e7ad8c31f9

The hypothesis suggests that good quality public-health programmes for improving child health are more available and being utilised by those families who need them least. The hypothesis also predicts that new interventions will tend to increase inequity since they will initially reach those who are already better off. It is only when the wealthy have reached a level of improvement--beyond which public-health interventions are unlikely to make more progress--that the poor begin to catch up and the inequity gap begins to improve. Thus, only over time will the gap be narrowed. The timing factor is therefore essential in the interpretation of the equity impact of new technologies. (Au)