REPORT FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT AND THE COUNCIL evaluating the main findings of the pilot studies established under Regulation (EU) 2016/792 on harmonised indices of consumer prices and the house price index
Date: 2025-12-18
Institutions: European Commission, Eurostat
Subjects: EU financing, EU statistics, consumer price, data collection, harmonisation of prices, national statistics, price index, price indexing, publishing of prices, statistical method

EN 

  EN 

   EUROPEAN COMMISSION  Brussels, 18.12.2025  COM(2025) 761 final  REPORT FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT AND THE COUNCIL evaluating the main findings of the pilot studies established under Regulation (EU) 2016/792 on harmonised indices of consumer prices and the house price index  
 
 
1. 

BACKGROUND 
Regulation  (EU)  2016/792 1  lays  down  a  common  framework  for  developing, 
producing  and  disseminating  the  harmonised  index  of  consumer  prices  (HICP),  the 
harmonised  index  of  consumer  prices  at  constant  tax  rates  (HICP-CT),  the  owner-
occupied housing price index (OOHPI) and the house price index (HPI). These four 
indices are together referred to as the ‘harmonised indices’. 

Article 8 of the Regulation allows the Commission to launch pilot studies, which are 
carried out on a voluntary basis by Member States. It can do this whenever improved 
basic  information  is  required  to  compile  the  harmonised  indices  or  the  harmonised 
indices need to be made more comparable. 

The  EU’s  general  budget  contributes  to  financing  these  pilot  studies,  where 
appropriate. 

These studies  must  assess the feasibility  of obtaining  improved basic information  or 
adopting new methodological approaches. 

The  Commission  (Eurostat)  must  evaluate  the  results  of  the  pilot  studies  in  close 
cooperation  with  Member  States  and  the  main  users  of  the  harmonised  indices.  In 
doing  so,  it  takes  into  account  the  benefits  of  improved  basic  information  or  new 
methodological  approaches  relative  to  the  additional  costs  of  producing  harmonised 
indices. 

Every  five  years,  in  accordance  with  Article  8(5)  of  Regulation  (EU)2016/792  the 
Commission  must  submit  a  report  to  the  European  Parliament  and  the  Council 
evaluating,  if  applicable,  the  main  findings  of  the  pilot  studies.  The  first  report  was 
submitted  in December  2020.  This  is  the  second  report,  due  for  submission  by  31 
December 2025. 
The  first  report 2  evaluated  the  main  findings  of  the  pilot  studies  for  the  2016-2017 
implementation period. This report covers pilot studies supported by grants from the 
EU’s  general  budget  for  2018-2022.  Further  rounds  have  been  launched  in  more 
recent years, but the relevant studies are ongoing and cannot yet be evaluated.  

The  total  budget  committed  to  grants  for  the  HICP  during  2018-2022  was 
EUR 5 548 290.  Around  65%  of  this  amount  was  dedicated  to  pilot  studies.  The 
budget committed to grants for the HPI/OOHPI was EUR 2 640 861. Around 20% of 
this amount was dedicated to pilot studies. 

1 Regulation  (EU)  2016/792  of  the  European  Parliament  and  of  the  Council  of  11 May  2016  on  harmonised 
indices  of  consumer  prices  and  the  house  price  index,  and  repealing  Council  Regulation  (EC)  No 2494/95, 
OJ L 135, 24.5.2016, p. 11, ELI: http://data.europa.eu/eli/reg/2016/792/oj. 
2 Report from the Commission to the European Parliament and the Council, Evaluating the main findings of the 
pilot  studies  established  under  Regulation  (EU)  2016/792  on  harmonised  indices  of  consumer  prices  and  the 
house 
eur-lex.europa.eu/legal-
14 December 
of 
content/EN/TXT/PDF/?uri=CELEX:52020DC0810&qid=1763626037139. 

COM(2020) 810 final 

index, 

2020, 

price 

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2. 

PILOT STUDIES ON HARMONISED INDICES OF CONSUMER PRICES 

2.1.  OVERVIEW 

There  were  two  broad  priorities  for  pilot  studies  on  the  HICP:  improved 
methodologies and new data sources for the HICP. 

These  priorities  reflect  the  continuing  need  for  the  HICP  to  be  relevant  and 
methodologically sound. Data collection  also  needs to  be modernised in  response to 
changes in consumption patterns, data availability and the evolving digital economy, 
while ensuring compliance with Regulation (EU) 2016/792. 

The  first  priority  for  new  methodologies  for  the  HICP  is  to  improve  the  statistical 
tools  used  to  compile  this  index.  The  aim  is  for  the  HICP  to  remain  theoretically 
sound,  robust  in  the  face  of  changing  consumption  patterns  and  consistent  with 
international best practice in price measurement. Studies financed under this activity 
have  involved  work  on  methods  to  capture  digitalisation,  quality-adjustment  and 
multilateral  index  methods.  These  themes  address  long-standing  methodological 
questions and new challenges arising from more complex consumption dynamics. The 
aim  is  to  ensure  that  the  HICP  measures  inflation  with  greater  accuracy  and 
comparability across Member States, while preparing for future statistical standards. 

The second priority is to incorporate data from alternative data sources into the HICP. 
The goal is to modernise data collection in line with the digitalisation of retail markets 
in order to improve coverage, efficiency and timeliness.  The  funded studies covered 
scanner  data,  web-scraped  data  and  inclusion  of  different  sources.  This  reflects  the 
need to adapt consumer price statistics to an environment where a lot of information is 
captured electronically. This requires not only new IT infrastructure but also revised 
statistical methods to incorporate diverse sources reliably. 

There  is  some  conceptual  overlap  between  the  two  priorities  even  though  they  are 
presented  separately.  Several  national  projects  necessarily  spanned  both  priorities, 
such as applying multilateral index methods to transaction data or web-scraped data. 
The report describes this work under the relevant methodological topic and provides 
cross-references where needed. 

2.2.  WORK COMPLETED 

Pilot studies on methods to capture digitalisation 

These pilot studies examined how the HICP can adapt to new forms of consumption 
in  the  digital  economy.  The  goal  was  to  identify  methods  and  data  sources  for 
measuring the prices of platform-based services  and cross-border internet purchases, 
and  to  improve  sample  design.  Work  was  done  to  test  the  feasibility  of  capturing 
sharing-economy 
from 
administrative  data.  Other  studies  included  cross-border  internet  purchases  and 
developed  methods  to  quantify  online  expenditure  shares  and  incorporate  them  into 
indices  for  categories  like  clothing  and  footwear.  Parallel  runs  showed  measurable 
effects  on  annual  rates.  Methodological  work  also  addressed  sample  design  for 
digitalisation and tested optimised allocation methods based on expenditure and price 
variance. 

services  and  experimental 

indices  were  produced 

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Pilot studies on methods for quality adjustment 

These pilot studies examined how quality changes in products can be better captured 
in the HICP to reduce bias from turnover or relaunches. The aim was to test and refine 
methods  and develop  tools where traditional overlap methods fall short.  The studies 
found that hedonic time-series models reflected quality-adjusted price dynamics better 
than  basic  averages,  especially  for  goods  with  frequent  model  changes.  Other  work 
addressed  supermarket  relaunches  by  combining  multilateral  indices  with  hedonic 
approaches  to  preserve  continuity.  Further  projects  created  aids  for  price  collectors, 
including decision trees for adjustment methods and expanded product characteristics 
for online and scanner data. 

Pilot studies on multilateral methods 

These  pilot  studies  explored  how  multilateral  index  methods  could  be  applied  to 
construct  HICP  series  from  large,  high-turnover  datasets,  such  as  scanner  and  web-
scraped data. They tested different approaches and assessed their performance under 
alternative splicing and chaining strategies. Several studies focused on product groups 
like food, clothing, appliances and electronics; and showed how the methods perform 
in  both  stable  and  volatile  markets.  Research  also  addressed  challenges  such  as 
(i) extending indices over time, (ii) deriving stratifications when product information 
is  limited  and  (iii) embedding  validation  tools  in  production  systems.  Overall,  this 
work provided solid evidence on the feasibility and design of multilateral methods for 
consumer price statistics. 

Pilot studies on scanner data 

Several  projects  investigated  using  scanner  data  from  retailers  for  the  HICP.  The 
focus  was  on  end-to-end  processes  ranging  from  data  acquisition  and  cleaning  to 
classification and index compilation. Work was done on building systems to manage 
large datasets by applying filters for outliers and designing workflows suited to high-
frequency,  high-turnover  goods  (such  as  food,  beverages,  household  appliances  and 
personal  care  items).  Some  pilots  also  tested  machine  learning  for  product 
classification  to  reduce  manual  coding.  Some  Member  States  also  explored  suitable 
index  formulas  and  trialled  bilateral  indices  and  chaining  strategies  for  monthly 
compilation. 

Pilot studies on web-scraped data 

These pilot studies tested the feasibility of web-scraping for the HICP in areas such as 
clothing,  electronics,  transport  services  and  tourism  products  (e.g. airfares  and 
package holidays). Projects developed automated scraping tools, sometimes combined 
with machine learning for product classification. They also explored statistical models 
to  improve  index  compilation.  In  some  cases,  web-scraped  data  were  linked  with 
traditional  or  scanner  data  to  produce  experimental  indices  (e.g. for  laptops,  hotel 
prices and consumer electronics). Operational use remains limited, but web-scraping 
has  already  replaced  or  been  added  to  manual  collection  for  certain  product  groups 
and has shown clear potential for wider application. 

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Pilot studies on incorporating prices from different data sources 

These  pilot  studies  investigated  how  different  data  streams  could  be  combined  to 
improve the coverage, timeliness and accuracy of the HICP. The main focus was on 
rents and other areas where traditional survey data are costly or incomplete. Work was 
done  on  including  administrative  data  on  private  rentals  from  industry  federations. 
This  substantially  increased  the  number  of  observations  and  geographical  detail 
available. Other studies  explored the use of online  advertising  data and  professional 
landlord datasets for rental indices. They tested matched-model and hedonic methods 
to  include  these  data.  Broader  pilots  developed  workflows  for  combining  scanner, 
web-scraped and field survey data into integrated workflows to address the challenges 
of classification, imputation and consistency across sources. 

3. 

PILOT STUDIES ON HOUSE PRICE INDICATORS 

3.1.  OVERVIEW 

The  pilot  studies  on  house  price  indicators  focused  on  three  main  priorities: 
(i) improving  the  frequency  and  timeliness  of  the  HPI  and  OOHPI,  (ii) making 
OOHPI weights more comparable and (iii) addressing specific methodological issues 
in OOHPI compilation.  

The first set of projects aimed to explore whether monthly or flash indicators could be 
produced  beyond  the  quarterly  frequency  and  85-day  deadline  currently  required  by 
Regulation  (EU)  2016/792.  This  is  to  increase  the  relevance  of  these  indicators  for 
users and help potentially incorporate the OOHPI into the HICP. A second group of 
projects was designed to align OOHPI weights with Regulation (EU) 2023/1470 3 to 
produce harmonised and updated time series. Finally, work was done on measurement 
issues to try and improve the treatment of land and structure components and to refine 
subindices (such as self-build dwellings, renovations and major repairs).  

These  activities  together  aimed  to  strengthen  the  methodological  foundations  of  the 
HPI  and  OOHPI,  improve  comparability  across  the  Member  States  and  prepare  for 
future integration with consumer price statistics. 

3.2.  WORK COMPLETED 

Pilot  studies  on  developing  an  HPI  and/or  OOHPI  at  monthly  intervals  and 
within a shorter deadline 

Regulation  (EU)  2016/792  requires  the  HPI  and  the  OOHPI  to  be  produced  at 
quarterly intervals and 85 calendar days after the end of the reference quarter. These 
projects analysed whether the indices can be produced at monthly intervals and within 
a shorter deadline. This is to increase their relevance for users and ultimately enable 
the  OOHPI  to  be  incorporated  into  the  HICP.  These  projects  covered  research  into 
data  sources  (e.g. web-scraping)  and  estimation  or  extrapolation  techniques.  Where 

3 Commission Implementing Regulation (EU) 2023/1470 of 17 July 2023 laying down the methodological and 
technical  specifications  in  accordance  with  Regulation  (EU)  2016/792  of  the  European  Parliament  and  of  the 
Council  as  regards  the  house  price  index  and  the  owner-occupied  housing  price  index,  and  amending 
Commission 
p. 1, 
Regulation 
ELI: http://data.europa.eu/eli/reg_impl/2023/1470/oj. 

2020/1148, 

18.7.2023, 

OJ L 181, 

(EU) 

4 

 
 
 
monthly  data  sources  were  different  from  the  data  sources  currently  used  for  the 
quarterly indices, methods for combining these sources needed to be investigated. 

Pilot studies in three Member States explored the feasibility of producing more timely 
and frequent house price indicators. A first objective was to alter the data collection 
process  or  to  look  into  different  data  sources.  A  second  objective  was  achieved  by 
finding estimation methods that allow a reliable index to be calculated with little (or 
less)  data  available.  More  precise  datasets  were  also  found,  resulting  in  reliable 
indices  with  a  higher  frequency.  The  studies  drew  on  new  data  sources  such  as 
construction prices, web-scraped information and improved administrative datasets. In 
doing  so,  they  demonstrated  both  the  potential  for  increasing  the  frequency  and 
timeliness of price indices and the limitations.  

Pilot studies on improving OOHPI weights 

Member  States  must  provide  Eurostat  with  OOHPI  weights  according  to  the 
breakdown set out in Article 22 of Regulation (EU) 2020/1148 4. This legislation did 
not specify data sources or methods to ensure comparability, so Eurostat started work 
on an implementing act to set out common quality standards. This process led to the 
adoption of Regulation (EU) 2023/1470, which lays down detailed specifications for 
these weights.  

Against  this  background,  two  Member  States  that  took  part  in  the  pilot  projects 
revised and updated their weights and indices. They were also given the opportunity 
to  carry  out  projects  in  this  field.  These  projects  were  expected  to  produce  weights 
consistent  with  the  Regulation.  Updated  time  series  of  weights  from  2010  onwards 
could then be compiled and the resulting data sent to Eurostat. 

Pilot  studies  in  two  Member  States  assessed  the  sources  of  the  weights  and  their 
alignment  with  the  draft  implementing  act  for  the  OOHPI  and  HPI.  The  issues 
explored  included  updating  weights  to  the  last  quarter  of  the  previous  year,  as 
required by the Regulation. The relevance and feasibility of calculating a weight for 
‘Existing dwellings new to households’ (which is also a subindex of the OOHPI) was 
also considered. 

4. 

EVALUATION OF THE PILOT STUDIES 

The  Commission  evaluates  and  approves  the  final  reports  on  the  pilot  studies.  The 
results are shared with national statistical institutes, EFTA countries and the European 
Central  Bank.  Projects  were  presented  at  annual  workshops  and  final  reports 
circulated  through  an  online  platform,  so  that  findings  could  be  shared  with  and 
discussed  by  statisticians.  This  exchange  helps  spot  best  practices  and  builds  a 
common  understanding  of  methodological  options,  and  this  in  turn  helps  improve 
HICP comparability. 

4 Commission Implementing Regulation (EU) 2020/1148 of 31 July 2020 laying down  the methodological and 
technical  specifications  in  accordance  with  Regulation  (EU)  2016/792  of  the  European  Parliament  and  of  the 
Council as regards harmonised indices of consumer prices and the house price index, OJ L 252, 4.8.2020, p. 12, 
ELI: http://data.europa.eu/eli/reg_impl/2020/1148/oj. 

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The pilot studies on methodological work came up with new tools and approaches for 
the HICP. Multilateral index methods were tested extensively and shown to be robust 
across  many  product  groups.  This  provides  strong  evidence  that  they  can  improve 
continuity  and  comparability.  Work  on  quality  adjustment  also  confirmed  that 
hedonic  techniques  improve  the  treatment  of  product  relaunches  and  rapid  quality 
change. 

Projects on digitalisation addressed emerging consumption channels and the redesign 
of  HICP  samples,  taking  into  account  online  data  availability.  Experimental  indices 
for accommodation and transport services were calculated from administrative data on 
sharing  platforms.  Surveys  were  also  used  to  capture  cross-border  internet 
expenditure.  Studies  on  sample  design  showed  that  efficiency  can  be  increased  by 
reallocating  resources  according  to  expenditure  weights  and  price  variance.  These 
approaches  demonstrated  viable  methods  for  addressing  digitalisation  within  the 
HICP. 

The pilots also tested and extended the use of new data sources. Projects on scanner 
and  web-scraped  data  expanded  the  range  of  alternative  sources.  Work  on  scanner 
data  progressed  from  feasibility  analysis  to  developing  production  systems.  Some 
Member  States  are  already  using  the  production  systems  for  selected  groups  of 
products and others are preparing to use them. Projects created routines for processing 
data,  developed  machine-learning  tools  for  classification  and  tested  methods  for 
handling missing attributes. Scanner data has proven effective in broadening coverage 
and increasing observation frequency, while also lowering collection costs. 

Web-scraping projects demonstrated the potential of automated data collection across 
consumer domains. Experience was acquired with scraping techniques, classification 
and  linking  to  existing  HICP  structures.  Several  pilots  also  tested  the  inclusion  of 
multiple  sources.  This  showed  that  combining  scanner  data,  web  data  and 
administrative data is feasible and improves coverage. 

The  studies  confirmed  that  methodological  innovation  and  new  data  sources  are 
closely linked. Many studies spanned both priorities by applying multilateral methods 
to  scanner  data  or  web  data.  They  also  clarified  the  conditions  under  which  new 
techniques can be successfully incorporated. Some studies did not lead to immediate 
use  but  nevertheless  they  provided  tested  approaches  that  help  gradually  modernise 
the HICP and HPI and lay the foundation for more accurate and timely statistics in the 
future. 

The pilot studies on house price indicators contributed to progress in several areas that 
are central to the future development of the HPI and the OOHPI. Work on improving 
timeliness  and  frequency  showed  that  monthly  compilation  is  technically  possible. 
This  is  particularly  the  case  when  administrative  records,  construction  data  or  web-
scraped  sources  are  used.  These  studies  also  highlighted  the  practical  difficulties  of 
ensuring sufficient coverage, stability of data access and consistency between monthly 
and quarterly indices. Nonetheless, the results provide a basis for assessing how flash 
or monthly indicators might eventually be added to the existing quarterly framework 
and make the statistics more relevant for policy use. 

Further  projects  addressed  the  quality  and  comparability  of  OOHPI  weights  and  the 
treatment  of conceptual  issues. The work on weights  allowed  Member States to  test 

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how national sources could be adapted to Regulation (EU) 2023/1470 to improve the 
consistency  of  historical  series  and  enable  more  regular  updates.  These  pilots  were 
exploratory in nature and not all results are ready for operational use. However, they 
provided  valuable  evidence,  clarified  methodological  challenges  and  contributed  to 
the  common  knowledge  base  needed  to  improve  housing  price  indicators  across 
Member States. 

5. 

CONCLUSIONS 

The  pilot  studies  funded  during  2018-2022  made  a  significant  contribution  to 
improving  EU  price  statistics.  They  strengthened  the  methodological  and  data 
foundations of the HICP and  contributed to progress on house price indicators. This 
helps Member States adapt to digitalisation, new data sources and evolving statistical 
standards.  Beyond  their  immediate  outputs,  the  projects  (i) expanded  the  pool  of 
(ii) improved  comparability  across  Member  States  and 
shared  knowledge, 
(iii) demonstrated  how  innovation  can  be  applied  in  practice.  The  Commission 
considers  the  pilot  studies  to  be  an  essential  tool  for  the  ongoing  modernisation  of 
price  statistics  and  will  continue  to  support  them.  It  also  encourages  the  Member 
States to actively use the financing opportunities it offers for pilot studies. 

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