Westpac's analysis suggests markets should not assume an automatic policy shift from a reinstated employment mandate, since its practical effect depends heavily on the nature of the shocks the economy faces rather than the mandate wording itself. In a typical demand-driven cycle, inflation and employment move together, meaning the dual mandate would change little about how the RBNZ sets rates. The more relevant scenario for current conditions is a supply shock, such as an oil price spike, where inflation and the labour market diverge, and an employment mandate could give the MPC room to tolerate above-target inflation for longer provided it retains confidence inflation will eventually return to target. Any NZD or rates market reaction to a Labour win is therefore likely to hinge less on the mandate change itself and more on signals about how the RBNZ's own confidence in medium-term inflation persistence would evolve under it.---Earlier:New Zealand Q2 retail sales have slowed much worse than expected---Labour wants employment back in the RBNZ's mandate, but Westpac says it would mostly matter when supply shocks, not demand shocks, hit the economy.Summary:New Zealand's Labour Party has pledged to restore the Reserve Bank's dual mandate targeting both inflation and maximum sustainable employment if it wins the November 7 election.Labour leader Chris Hipkins said Sunday the party's fiscal strategy is about ensuring growth is felt in household budgets and pay packets, not just headline figures.The Reserve Bank currently operates under a single mandate to keep inflation between 1% and 3%, targeting 2%.The dual mandate was introduced in 2018 under the previous Labour-NZ First government, with then-Finance Minister Grant Robertson adding the employment focus, before the current Coalition Government removed it in 2023.Westpac commentary says the mandate would make little practical difference during demand shocks, when inflation and employment typically move in the same direction.Westpac notes an employment mandate could matter more during supply shocks, such as an oil price spike, by giving the RBNZ more flexibility to let inflation run above target for longer, though this depends on the MPC's confidence that core inflation will return to target over the medium term.New Zealand's opposition Labour Party has pledged to restore the Reserve Bank's dual monetary policy mandate, reinstating a focus on maximum sustainable employment alongside inflation control if it wins the November 7 general election. Labour leader Chris Hipkins announced the policy on Sunday, saying growth means little if it is not felt by New Zealanders in their pay packets, household budgets or future prospects, and framing the party's fiscal strategy around ensuring that translation happens.Under the current framework, the Reserve Bank operates with a single mandate to keep inflation within a 1% to 3% band, with an explicit 2% target. The dual mandate model was originally introduced in 2018 by the previous Labour-NZ First government, when then-Finance Minister Grant Robertson added the employment objective alongside price stability. The current Coalition Government removed that employment focus in 2023, returning the Bank to a single inflation mandate.Commentary from Westpac assesses what reinstating the dual mandate would actually mean for the conduct of monetary policy, concluding the answer is largely dependent on the type of shock the economy faces. In most periods, the bank notes, shocks affecting the economy are demand-driven, meaning factors influencing inflation and the labour market tend to push policy in the same direction, since weaker demand and employment are usually associated with lower inflation. In that scenario, Westpac argues, a dual mandate would change little about how policy is set.The more significant divergence, according to Westpac, arises during supply shocks, such as the current oil price spike, when inflation and the labour market can move in opposite directions. An employment mandate in that context could give the Monetary Policy Committee more flexibility to let inflation run above target for longer, allowing a more gradual policy adjustment. Westpac cautions that this flexibility would be more likely to be used if core inflation pressures are seen as likely to return to target over the medium term, meaning the MPC's own confidence in that persistence would ultimately determine how much difference the mandate makes in practice.Westpac also flags a longer-term risk in accommodating temporary inflation shocks under a broader mandate, warning that doing so can prove damaging if elevated inflation becomes embedded in business pricing behaviour and wage expectations. The commentary underscores that in the long run there is no genuine trade-off between inflation and employment, a caveat that frames the debate over Labour's proposal as less about the mandate's wording and more about how it would be applied in practice by the Reserve Bank's decision-makers. This article was written by Eamonn Sheridan at investinglive.com.