From the 1st April 2011, the responsibility for the collection of data and production of official labour market and economic statistics transferred from the Department of Enterprise, Trade and Investment to the Northern Ireland Statistics and Research Agency (NISRA), an agency of the Department of Finance and Personnel (DFP) . This transfer mirrored the position in Great Britain where most business surveys and labour market data collection and statistical production have been transferred from the departments with policy responsibilities to the Office for National Statistics (ONS). However, it is important to note that there are no planned changes to the production of economic and labour market statistical publications and outputs as a result of the transfer.
IOP Quality Report
Adobe Acrobat IOP Quality Report (48KB)
Report on the Review of the Quarterly Inquiry into Sales of Industry, April 2005
Adobe Acrobat IOP Review, 2005 (135KB)
Revisions to IOP Estimates
It is normal practice for Index of Production (IOP) estimates to be revised. Results, particularly for the latest IOP quarter, are provisional and subject to revision as more up to date information becomes available. These revisions will occur primarily in light of (a) late responses to surveys and administrative sources, (b) where cross survey congruence checks provide more accurate data - e.g. data can be revised back and finalised once comparisons have been made with the current year Annual Business Inquiry (ABI) or Manufacturing Sales & Exports returns and (c) where there are revisions to seasonal adjustment factors which are re-estimated every quarter.
Very few statistical revisions arise as a result of ‘errors’ in the popular sense of the word. All estimates, by definition, are subject to statistical ‘error’ but in this context the word refers to the uncertainty inherent in any process or calculation that uses sampling, estimation or modelling. Most revisions reflect either the adoption of new statistical techniques, or the incorporation of new information, which allows the statistical error of previous statements to be reduced. Only rarely are there avoidable ‘errors’ such as human or system failures, and such mistakes are made quite clear when they do occur.
The Index of Production was published for the first time on a Standard Industrial Classification 2007 (SIC07) basis in October 2011. This has an impact on the type of businesses classified as production sector. For example, publishing activities move from the production to the services sector and sewerage and waste disposal moves from services to the production sector. Within the production sector there are some new groupings of businesses. The previous IOP data were collected on a SIC03 basis and it has been converted to approximate the SIC07 coverage.
Revisions Policy
The IOP Revisions policy which outlines the treatment of planned and unplanned revisions can be accessed via the link below
IOP Revisions Policy(31KB).pdf
Revisions Triangles
Historically, the IOP bulletin has contained information on Revisions Triangles. These triangles presented a summary of the differences between the first estimates of growth published and those published 3 years later for the same reference period. A statistical test has been applied to the average revisions to growth to find out if it is statistically significantly different from zero. This quarter we have moved to publishing on a SIC07 basis. As the coverage of the Index (and the broad industry groupings) is different between SIC03 and SIC07 it is not possible to compare the results provided in this bulletin with those published in July 2011. This quarter the data for Q1 2011 and earlier have been converted to approximate the SIC07 coverage and are therefore not strictly revisions. As a result no Revisions Triangles are available this quarter. Further information on the construction of SIC07 revisions triangles will be announced in due course.
Future Improvements
A timetable of further improvements to the Index of Production can be accessed via the link below.
