Income tax and tax incidence
Posted October 25, 2007
on:There seems to be a significant debate between the left and right wing blogs about whether New Zealand is over-taxed or not. However, there is one thing that both sides agree on, if taxes are cut by $1,000, this gives people $1,000 more to spend. This is the point I’m going to discuss.
Households receive a net wage, which is their gross wage – income tax. The household requires a certain net wage before it will enter the labour market (say the benefit + the opportunity cost of leisure time), and may also require a premium to choose one firm before another firm (when labour supply is restricted).
Now the gross wage + non-labour costs (which we will assume are exogenous, even though they aren’t really 🙂 ) is the cost to the firm of hiring that employee. If taxes fall, the net wage the household receives would be higher. However, the relationship between employers and employees determines the gross wage. If the employer knows that taxes will fall, they can reduce their employees gross wage and leave their net wage the same (I know that firms often can’t do this because of labour laws and wage stickiness, however in a dynamic sense they could just reduce the rate at which they increase an employees wage). Ultimately, the division of the tax depends on the relative bargaining power of the different agents.
If there were ‘many’ firms and ‘many’ employees, the incidence of tax would depend on the relative elasticities of demand and supply for labour. Often labour demand is assumed to be relatively elastic while labour supply is highly inelastic. In this case most of the tax is borne by the employee and so a cut in taxes will mainly benefit them.
However, if we have a high rate of unemployment, labour supply will become relatively more elastic, which implies that some of the burden shifts onto employers.
If we have a monopoly firm and many (homogeneous) low-skilled employees (flat labour supply curve) the tax burden will be fully taken up by the firm. This is because the monopoly will only want to pay enough to get the employees to work, and so the net wage will be set at the reservation level. If you cut taxes you cut the gross wage required to get this net wage. Note: This result would not hold with asymmetric information (worker effort) or heterogeneous agents (as a higher net wage would then be required to intice more workers – labour supply would be upward sloping).
Ultimately, where the burden of income tax falls is a difficult issue, and depends on the specifics of the labour and goods markets. However, it is not clear cut that if my taxes are cut I would end up with that much extra money. As a result, we have to realise that a cut in income taxes will result in a reduction in firm costs as well as an increase in consumers spending power.
16 Responses to "Income tax and tax incidence"

So tax cuts are going to be inflationary whenever they come from a surplus? Meaning when tax cuts are most justified they are most harmful inflation wise.
Another argument for not letting a surplus grow to absurd levels, I suppose.


Sure, do you think the benefit of running a surplus can change at large levels?
Is there a prudent level of surplus? If you cannot cut tax when the surplus is THIS high, when can you ever do it?


I agree that if he does believe the second thing there is no way he would ever say it, as it would come across as “we have been lucky and dont deserve this growth”. Calling it a windfall would offend everyone.
Tax cuts could be prudent, even if we are currently exceeding the natural rate, if policies were in place to remove bottlenecks in produciton and increase the natural rate. Agree?
Perhaps this is what Howard and Costello were trying to do in Australia (after many years of tax cuts and continuing surpluses, despite increasing federal budgets) with their Work Choice legislation.


What about a reduction in GST, withholding tax, or the business tax rate*? Same impact?
*Without an offsetting increase in the cost of Labour, ie kiwisaver.


Quarterly inflation is down below 2%, surely now would be the time for tax cuts? (Or more precisely, last year WOULD have been the time for tax cuts.)


“However, there is one thing that both sides agree on, if taxes are cut by $1,000, this gives people $1,000 more to spend.”
I’m a bit late commenting to this post but I don’t particularly agree with this.
While some people likely would just spend this extra money on shoes and plasma tvs and others would save the extra money, I think there’s a third group of people who are currently spending beyond their means with large mortgages or overdrafts that are slowly increasing. If these people continue to spend the same amount, but can actually afford it now, what sort of affect do you think this would have?


[…] moons ago we discussed tax incidence – I think it is time to run with this again, taking for granted some of the assumptions about the […]

October 25, 2007 at 1:20 pm
So what you are saying is that cutting income taxes is more likley to have a net zero impact on inflation? Increased spending, but decreased costs?
How would that work with Working For Families*? Where the employer doesnt have the knowledge of the benefit payment?
Would that increase spending power (and demand) and keep costs the same?
* It would be very interesting to see the number of Exculsive Brethren that are eligble for WFF payments. They have large families dont they? Wouldnt it be funny if WFF funded EBs political campaigns!