This paper examines the effect on a measure of social welfare of an in-work payment, involving a discontinuity at an hours threshold. Social welfare is defined in terms of individuals' utilities, which depend on leisure and net income. The in-work payment augments a modified minimum income...

This paper examines the optimal direction of marginal income tax reform in the context of New Zealand, which recently reduced its top marginal income tax rate to one of the lowest in the OECD. A behavioural microsimulation model is used, in which social welfare functions are defined in terms of...