Scottish teachers' pay and conditions are agreed and set at national level - at least for the time being, while the Scottish Negotiating Committee for Teachers still exists.
That means that an unpromoted history teacher will earn the same in Wick, Glasgow or Galashiels.
But teachers who want to retire early - and there is increasing interest in doing so, not to mention pressure from councils to make way for younger entrants - face a postcode lottery when it comes to the packages on offer both across local authorities and even within them.
It is a grievance that has long simmered under the surface - but one that unions are powerless to address.
Drew Morrice, assistant secretary of the EIS teaching union, says they have checked whether the terms of the Equality Act could be used to ensure equal treatment for council employees applying for "premature retirement compensation", as early retirement packages are called.
There appear to be no legal grounds to force councils to offer the same terms in such circumstances, he says. So if councils seek to target teachers whose salaries were conserved under the national teachers' agreement - i.e. principal teachers who have kept their salary after being moved into a faculty which they do not lead - they are perfectly entitled to do so.
Likewise, if a council finds that fewer pupils than expected are choosing history as an option in secondary, and more are choosing geography, it can and will target history teachers for early retirement packages, leaving their colleagues in geography disgruntled.
Scotland's 32 authorities take 32 different approaches, as a comprehensive survey by TESS shows. Our questionnaire on early retirement deals received responses from 31 of the 32 councils (Dundee failed to answer).
A varied picture
Until April last year, the pension rules for teachers allowed local authorities to offer early retirement deals to anyone aged 50 and above. Our survey shows that six - Inverclyde, Aberdeen, East Dunbartonshire, Falkirk, Scottish Borders and South Lanarkshire - have done so at some point in the past three years.
Since April 2010, early retirement deals have only been available for teachers from the age of 55. Most councils offer these, but in Angus, early retirement packages were only offered to teachers aged 59 or over.
What's more, there are considerable variations when it comes to enhancement terms. East Dunbartonshire and Renfrewshire have offered up to 6.66 years' enhancement, while Edinburgh has offered less than a year. In between are a whole range of terms.
Offering teachers an early exit from their profession is a well-used workforce planning mechanism - and just as teacher employment figures have been subject to significant variation, so has the nature of deals on offer.
Ken Cunningham, general secretary of School Leaders Scotland, estimates that 102 secondary heads have retired in the past three years - that's around a quarter of the total of secondary heads in Scotland - and around 50 of these have gone under the age of 60.
"This is a significantly high turnover," he comments.
The reasons for early departures are open to speculation, but concerns about the impact of changes to pension arrangements by the Government are likely to be a very strong impetus.
Some headteachers have chosen to go early to allow their successor to lead the school into Curriculum for Excellence; others have left if their school was about to move to a new building.
There are, however, more sinister reasons for choosing an early exit, according to Mr Morrice at the EIS. He reports headteacher members going early because of the "scunner" factor - and cites, in particular, headteachers' unwillingness to operate the much stricter attendance management rules being implemented by local authority employers.
"Heads are being asked to be more rigorous. If a member of staff is off sick for three days, they have to call them in for a meeting; if they are off for another three days, they have to send out a warning letter.
"Many headteachers are appalled by the process - it makes working relationships very difficult because often they know why someone is off and sympathise," he says.
Heads feel under pressure to get poor attenders out of the profession and their jobs filled by people desperate to work - supportive measures are being put to one side, he claims.
Many of these sentiments are echoed by Mr Cunningham, who says another trigger for heads retiring early is the stress of having to do far more with far less. Some heads are lucky enough to work for supportive employers, whose attitude in tight financial circumstances is, "We're all in this together - let's support each other"; others are not, he says.
Then there's the fear factor. Both the EIS and SLS report persistent rumours whirling round the profession that the Government plans to tax the retirement lump sum at 40 per cent. Until the Budget next month, these rumours are likely to continue.
The "winding down" scheme for older teachers who want to do fewer hours as they approach retirement without taking a hit on their pension was introduced under the national teachers' agreement 10 years ago. Figures from the Scottish Public Pensions Agency show that 938 teachers have applied to the scheme in the past decade. But whether it survives the review of the teachers' agreement, chaired by Gerry McCormac, remains to be seen - the unions like it; employers are less enthusiastic.
Attempts by the Scottish Government to persuade councils to operate a "teacher refresh" scheme have been largely unsuccessful. Although a handful have operated their own, all but Falkirk have snubbed the Government's offer of extended borrowing consent to pay for teachers to leave early.
"Councils are not going to put themselves further in debt at this difficult time," says John Stodter, general secretary of the Association of Directors of Education in Scotland. A better move would have been to offer direct financial support to make the numbers work. After all, he points out, Education Secretary Michael Russell was able to find some additional money for councils in the November deal with Cosla to provide jobs for teachers coming out of probation.
But the best way of introducing greater stability into workforce planning, Mr Stodter argues, would be to enable education departments to plan on a five-yearly basis instead of the current situation where directors are handed a budget in February, to implement in April for the next 12 months.
"But I can't see us getting that ever," he concedes.
Additional research by Julia Belgutay
What you should know about taking early retirement
Teachers need to be clear about what the elements of an early retirement package mean. Most councils will set out the various figures for them, although some unions say that the confidential nature of a teacher's package allows a council to be more generous with some employees than others. On the other hand, some councils have agreed severance packages which offer the same deal to all.
If a teacher takes premature retirement, their main scheme benefits are actuarially reduced, but the employer provides mandatory compensation to make up the shortfall.
For a 58-year-old, the employer needs to pay 10 per cent of the pension and lump sum; for a 55-year-old, it's 22.3 per cent. Thus, the cost of the package rises significantly between the two ages if teachers have similar length of service and salary.
The employer may choose to sweeten the package by offering discretionary service enhancement. The downside of this for the council is that it represents a recurring cost.
Alternatively, an option sometimes known as "teacher refresh" allows a council to buy pension in blocks of pound;250 by making a one-off payment to the Scottish Public Pensions Agency, thus saving money. The younger you are, the cheaper it is to purchase additional pension, but the actuarial reduction on collecting early is greater. If an employer purchases pound;2,000 additional pension for a 58-year-old, they will receive pound;1,800 per annum; the 55-year-old will only get pound;1,546. Teachers then take an actuarially reduced pension as they access benefits before their normal pension age. Few councils have chosen to go down this route.
Some councils have started to insert a clause into early retirement deals requiring teachers to give a commitment not to seek supply work in the council.
Where the deals are
The number of years' enhancement on pensions that councils have offered with early retirement packages over the past three years
Western Isles 2
Perth and Kinross 2
North Lanarkshire 4
Argyll and Bute 2
East Dunbartonshire 6.66
West Dunbartonshire 4
North Ayrshire 2
South Ayrshire 3
Dumfries and Galloway 4
Scottish Borders 0.86
Midlothian less than 1
West Lothian 0
Information not available for:
EARLY RETIREMENT: COUNCIL PROVISION
Have you taken advantage of the Government's so-called "teacher refresh" scheme or do you have one of your own?
Yes: 1 out of 31 councils
Scheme of their own: 9 out of 31 councils
21 out of 31 councils
Over the past three years have you made provision for the premature release of teachers through early retirement compensation?
No: 6 out of 31 councils
Yes: 25 out of 31 councils
What age group was targeted?
No specific age group targeted