It happens, possibly more than policymakers know, in the small business, minimum wage service industries.
The owners of the business don't think it unfair since on slow days they are losing money too.
They are treating their staff as partners in a business loss, which would be fine if they were also treating them as partners in profits.
But they know the Christmas bonus they happily pay in good years like this one hardly amounts to an equal share of the profit they have made. Nor need it be.
Marxists believe it is immoral for someone to profit from the labour of another. They are wrong in my view because the one profiting is usually the one who is taking the risk.
When plenty of work is coming in an employer has a perfect right to do very well, probably making much more than the worker receives for the work.
But the deal is, or should be, that when not enough work is coming in the employee is paid regardless and the employer takes the loss.
Fundamentally, employment is a contract between people with different priorities. Everybody wants wealth and security but people differ on which is more important to them.
Employees have traded the profits of their labour for a more predictable income, employers accept less security in a quest for profit.
That's how a fair and prosperous economy works. Security is more important than wealth to most people but thankfully not to all.
Without the profit-seekers we'd all be poorer.
Trade unions that press for profit-sharing schemes are inviting the same criticism.
They do not offer wage reductions in the event of a loss. They will not be trading their members' security for a share of the profit. Like the unthinking employer the union wants both.
There ends the lecture. It is easier to say what is wrong with zero-hour contracts than to write a law against them.
Andrew Little gave the problem only passing mention in his first big speech in Auckland this week as leader of the Labour Party.
He was more intent upon widening Labour's appeal by including small business owners, the self-employed and mid-level income earners in the ranks of those he portray as struggling to get ahead.
Facing a Prime Minister who has just increased his party's seats at a third successive election, Little can give his party plenty of time to suggest a legislative solution to the zero-hour problem.
But he should make it Labour's mission to propose one without delay.
The law may need to insist that employment paid at an hourly rate must specify an agreed weekly minimum of hours.
If it is less than 40 hours at least it is a certain income. The uncertainty of these people's earnings from one week to the next must be the worst part of their present arrangements.
God knows how they do household budgets. Since they are probably on the minimum hourly wage anyway, it would be no wonder if they decided a slightly lower but more secure income on social welfare was a better option.
That's a thought that might prompt the Government to seek a solution. National is always reluctant to impose more regulations on the labour market because they can cost jobs.
A minimum hours commitment would add to the risk faced by a small business owner who contemplates adding another employee to his fixed costs.
There may be a cost to the country too in less employment and economic activity.
But if it means that people who now are on fulltime commitments move to more certain part-time contracts that allow them to take additional jobs, we might see more real employment overall and more economic activity.
More importantly, these people might take home a higher income every week.
The Government knows New Zealand's general income level is too low.
It should do something about this while the good times last. If it wants to leave the job to Labour it might as well knock off early too.
