Northern Ireland's sectarian problems inflate the policing bill here by as much as £500m a year, an official report has found.
The figure is contained in a study for Government that gives an estimate of up to £1.5bn for the annual total cost of the province's divisions.
The report was commissioned by the Office of the First Minister and Deputy First Minister (OFMDFM) prior to the restoration of devolution.
It examines the drain on the public purse that violence, segregation and duplication of services for the two communities causes.
Entitled 'Research into the financial cost of the Northern Ireland divide', the document was compiled by consultants at Deloitte, with input by senior Government officials and the PSNI.
It found that in one year alone, £478,000 was spent on policing in Northern Ireland for every 1,000 people in the province. The figure for England and Wales was £183,000.
Based on these figures, the report concluded that the "maximum additional cost of policing due to the sectarian divide is potentially £504m per annum".
The Deloitte researchers also spelt out the impact that decades of violence and negative publicity has had on Northern Ireland's economy.
This included the loss of 27,600 jobs in the period 1983 to 2000, costing the economy on average £12.5m a year.
Spending on industrial development per head of the population here was almost three times the level of that the UK as a whole in one year recently.
In addition, Government has given support to "high-risk" investment projects like the ill-fated DeLorean car factory, the study noted.
The consultants also concluded that some £49m has been lost annually in tourism revenue on average, with potential visitors being confronted with " images of civil unrest, terrorist outrages and periodic sectarian strife" in the world's media.
The cost of the divide in the public housing arena was given as £24m a year, of which £21m is attributed to inefficiencies resulting from segregation and sectarian interfaces.
Civil unrest has blighted districts, leading to houses lying empty and, in some cases, being demolished. In other areas, meanwhile, waiting lists are growing while new homes are being built.
The report also stated: " The marking of territories according to tradition has led to inefficiencies in meeting housing need. In particular, there are a significant number of additional social housing units developed through the social housing development programme whilst other social housing lies vacant for reasons related to societal divide."
In education, a £10m estimate was given for the cost of the divide.
On top of this, the Deloitte consultants outlined details of 165 additional school bus runs per day which need not occur in the rest of the UK. They found that this required 45 extra buses, costing some £2.45m.
The study also quoted £13m as the annual sum spent on community relations, and £7m on support for victims.
In conclusion, the report stressed that the examination of the costs of division was "particularly complex" and quantifying the figures had "proved difficult".
It further stated that the £1.5bn overall total "could be considered to be the upper limit".