Annual revision 2026 Last update: 5 March 2026
2026 Annual Revision
for the Industrial Production Index
and the Index of Production in
Construction
The Industrial Production Index (IPI) and the V olume Production Index in Construction (IPVC) are reviewed
annually in order to carry out a number of methodological updates. On the occasion of the publication of the first
figures for January 2026 (5 March 2026), the indices may therefore be revised.
I. Updates carried out in 2026
Annual review of the products used to monitor production
The IPI series undergo an annual review process on a 7-year cycle. Each year, one seventh of the surveyed
branches is reviewed in order to improve the measurement of production in these branches. This examination
and the updates that may result from it aim to ensure the robustness of the indices and adapt them to economic
or technical developments, in particular by including the monitoring of new products and removing those whose
production has become very low. The changes resulting from the 2026 review are presented in Annex 1. The
series incorporating these changes are recalculated over the last four years: 2022 to 2025. This may lead to
revisions over the period.
Update of productivity coefficients for branches monitored in hours worked
For the branches monitored in hours worked (Annex 2), the productivity coefficients, which convert hours
worked into volume production, have been updated using data from the final 2022 accounts and the semi-final
2023 accounts of the national accounts. This leads to specific revisions for these branches since 2022.
In industry, this update results, all other things being equal, in an upward reassessment of the manufacturing
index by 0.3 index points in 2022 and 2023, then by 0.5 index points in 2024 and 2025. This is mainly explained
by the 1Cother manufacturing industries including repair and installation (CM) 1D branch (which accounted for
15 % of manufacturing value added in 2023), whose productivity was significantly revised upward in the
national accounts, leading to a revision of this branch’s index of +2.1 points in 2022 and 2023, then +4.0 points
in 2024 and +4.2 points in 2025.
In construction, which is monitored entirely in hours worked, the revisions to the IPVC are more moderate: -0.8
points in 2022, +0.8 points in 2023, and +0.2 points in 2024 and 2025.
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Annual revision 2026 Last update: 5 March 2026
Update of weights
The IPI and IPVC are chain-linked indices with weights updated annually. The weights are calculated from data
on gross value added at basic prices by branch, sourced from the annual national accounts 1. The latest available
annual data are the final accounts for 2022 and the semi-final accounts for 2023. The weights of the IPI and
IPVC have therefore been updated with these data for the period 2023 to 2025. The data from the semi-final
accounts for 2023 are also used to calculate the year 2026.
Update of SA-WDA models
The series are adjusted for seasonal variations (SA) and working day effects (WDA). The estimation of these
effects is carried out using the X13-Arima method of the JDemetra+ software at the class level of NACE Rev. 2.
The SA-WDA indices for higher-level items are obtained by aggregating the SA-WDA indices of the classes that
compose them. Each year, the models underlying the X13-Arima method are re-estimated. As the change to the
time period over which the series profile was updated (from 2017 instead of 2012 previously) was implemented
last year, the changes to the SA-WDA models are smaller this year.
II. Revisions for 2022-2025
In addition to the usual revisions for the last months of the period, linked to late responses from enterprises
surveyed about their production at the end of 2025, the main factors that may lead to revisions are therefore
those mentioned above:
(i) the review of monitored products for certain branches;
(ii) the update of productivity coefficients for certain branches;
(iii) the update of weights for the period 2022 to 2025;
(iv) the update of SA-WDA models.
For manufacturing as a whole (CZ), the revisions to the SA-WDA index range from -0.3 to +0.9 index points
over the 2022-2025 period (Figure 1). Revisions to monthly changes range from -0.5 to +0.5 percentage points
over the 2022-2025 period. The revisions are mainly due to the annual product review, the update of weights,
and the update of productivity coefficients.
For construction (FZ), the revisions to the SA-WDA index are somewhat larger. In index points, they range from
-1.1 to +1.3 points over the 2022-2025 period (Figure 2). Revisions to monthly changes range from -1.2 to +0.6
percentage points over the 2020-2025 period. The construction indices were not subject to an annual review in
2025. The revisions are mainly due to the update of productivity coefficients and the update of weights.
1 For more information on these weights, please refer to the Insee Méthodes No. 133 on the Industrial Production Index.
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Annual revision 2026 Last update: 5 March 2026
Figure 1: Revision of the SA-WDA index in manufacturing (CZ)
Source : Insee
Figure 2: Revision of the SA-WDA index in construction (FZ)
Source : Insee
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Annual revision 2026 Last update: 5 March 2026
III. Preparation for the upcoming nomenclature change in 2027
Currently published under the French classification of activities (NAF) of 2008, the Industrial Production Index
(IPI) and the V olume Production Index in Construction (IPVC) will be published under NAF 2025, starting from
the publication relating to the figures for January 2027 (scheduled for March 2027). The series published under
the new nomenclature will then be back-calculated over the past.
In order to anticipate this work, for a number of product groupings (Annex 3), enterprises have been surveyed
from January 2026 at a finer level than in 2025, making it possible to build series in both the old and the new
nomenclature. This finer level of survey may lead, for the series concerned, to changes in response behaviour in
2026 compared to the past.
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Annual revision 2026 Last update: 5 March 2026
Annex 1: branches updated after the annual review of the products
NAF class
code NAF Rev. 2 class label Modification made
1020Z Processing and preserving of fish Product grouping
1051C Manufacture of cheese Addition of products
1051D Manufacture of other dairy products Grouping, additions and removal of
products
1086Z Manufacture of homogenised and dietetic food Product grouping
1089Z Manufacture of other food products n.e.c. Splitting and removal of products
1091Z Manufacture of prepared feeds for farm animals Addition of products
1392Z Manufacture of textile articles except apparel Addition of products
2314Z Manufacture of glass fibres Addition of products
2399Z Manufacture of other non-metallic mineral products
n.e.c. Addition of products
2420Z Manufacture of tubes, pipes, hollow profiles and
related fittings, of steel Addition of products
2432Z Cold rolling of narrow strip Addition of products
2640Z Manufacture of consumer electronics Deflator change
2670Z Manufacture of optical and photographic equipment Deflator change
2711Z Manufacture of electric motors, generators and
transformers Removal of products
2740Z Manufacture of electric lighting equipment Addition of products and deflator
change
2790Z Manufacture of other electrical equipment Addition of products
2811Z Manufacture of engines and turbines, except aircraft
and vehicle engines Addition of products
2830Z Manufacture of agricultural and forestry machinery Addition of products and deflator
change
2841Z Manufacture of metal forming machinery and
machine tools Deflator change
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Annual revision 2026 Last update: 5 March 2026
2892Z Manufacture of machinery for mining or
construction Addition of products
2893Z Manufacture of machinery for food processing Removal of a product
2910Z Manufacture of motor vehicles Update of weights for each vehicle
()
(): in order to calculate the production index for motor vehicle manufacturing, the quantity produced of each
vehicle model is weighted by the recommended pre-tax selling price during the base year (currently 2021).
These selling prices, which had not been updated since the 2015 base change, have been updated in this
publication
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Annual revision 2026 Last update: 5 March 2026
Annex 2: Industrial activity branches affected by the update of the
coefficients of productivity
NAF class
code NAF Rev. 2 class label
% of the class value
added in 2023
covered by hours-
worked monitoring
2511 Manufacture of metal structures and parts of structures 31
2530 Manufacture of steam generators, except central heating hot water
boilers 100
2540 Manufacture of weapons and ammunition 100
2899 Manufacture of other special-purpose machinery n.e.c. 91
3011 Building of ships and floating structures 100
3012 Building of pleasure and sporting boats 100
3020 Manufacture of railway locomotives and rolling stock 100
3030 Manufacture of air and spacecraft 15
3311 Repair of fabricated metal products 79
3312 Repair of machinery 25
3315 Repair and maintenance of ships 100
3316 Repair and maintenance of aircraft and spacecraft 100
3320 Installation of industrial machinery and equipment 26
How to read: In branch 2511 “Manufacture of metal structures and parts of structures”, the products monitored in hours worked
represent 31% of value added in 2023.
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Annual revision 2026
Last update: 5 March 2026
Annex 3: Activity branches subject to monitoring at a finer level of product
grouping in 2026 than in 2025
NAF class
code
NAF Rev. 2 class label
1320
Weaving
1413
Manufacture of outerwear
1414
Manufacture of underwear
1419
Manufacture of other wearing apparel and accessories
1621
Manufacture of veneer sheets and wood-based panels
1623
Manufacture of assembled parquet floors and other builders' carpentry
1624
Manufacture of wooden containers
1629
Manufacture of other products of wood; manufacture of articles of cork, straw and plaiting materials
2014
Manufacture of other organic basic chemicals
2221
Manufacture of plastic plates, sheets, tubes and profiles
2222
Manufacture of plastic packing goods
2223
Manufacture of builders' ware of plastic
2229
Manufacture of other plastic products
2453
Casting of light metals
2521
Manufacture of central heating radiators and boilers
2561
Treatment and coating of metals
2640
Manufacture of consumer electronics
2711
Manufacture of electric motors, generators and transformers
2712
Manufacture of electricity distribution and control apparatus
2752
Manufacture of non-electric domestic appliances
2790
Manufacture of other electrical equipment
2811
Manufacture of engines and turbines, except aircraft and vehicle engines
2821
Manufacture of ovens, furnaces and burners
2823
Manufacture of office machinery and equipment (except computers and peripheral equipment)
2825
Manufacture of industrial air conditioning and refrigeration equipment
2829
Manufacture of other general-purpose machinery
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Annual revision 2026 Last update: 5 March 2026 3011 Building of ships and floating structures 3030 Manufacture of air and spacecraft 3091 Manufacture of motorcycles 3101 Manufacture of office and shop furniture 3250 Manufacture of medical and dental instruments and supplies 9