General dataset description 
The Market Monitoring Survey (MMS) tracks the functioning of 52 (40 in the 2017 edition) consumer markets across the EU, Iceland and Norway.
The data available in this database is published by DG Justice and Consumers within the Consumer Markets Scoreboard: 
http://ec.europa.eu/consumers/consumer_evidence/consumer_scoreboards/index_en.htm
Contact person/organisation
JUST-03@ec.europa.eu
Variables collected 
This survey provides data for the Consumer Markets Scoreboard, yielding information on consumer markets in terms of comparability (1), trust (2), consumer problems and related detriment (3), satisfaction with respect to expectations (4), choice (5), consumer complaints (6) and switching (7). The first five indicators are applicable to all the markets and form the Market Performance Indicator ("MPI")  a composite index serving as the basis for the main ranking of the markets and ranging theoretically from 0 to 100.  
Unit of measures used
Values are expressed as averages and percentages. Composite indexes on market performance are computed as averages of different components. Indexes range from 0 to 100 while components range from 0 to 10.
Classifications used
The market monitoring survey measures consumer experiences and perceived conditions in goods and services markets, per country as well as by socio-demographic groups such as gender, age, education, occupation and financial situation. 
Target population and methodology of data collection
The target population comprises consumers who are aged 18 and plus (for each market those who bought the product/service referring to that market).
Data are available for EU28 (EU27 before 2013), plus IS and NO. 
In every country, a random sample representative of the target population is drawn. For this purpose, the questionnaire foresees, for each market, a screening question to verify if the person interviewed bought the product/service within a time frame that varies according to the product/service concerned (and therefore he/she can be included in the sample for that market). 
Interviews are conducted via telephone (fixed and mobile).
The sample size is equal to around 500 respondents per country and per market surveyed (except for LU, MT, CY and IS: 250). 
The survey has been annual from 2010 to 2013 and is conducted every two years from 2013 onwards.
Recommended uses and limitations (as a result of methodological changes)
The Consumer Markets Scoreboard has undergone a thorough methodological revision. As a result of this, some changes were introduced in the survey methodology in 2015:
*  the Market Monitoring Survey for the first time collected data on the importance that respondents attach to each of the MPI's components  (comparability, trust, problems and detriment, expectations and choice) in every market, and the MPI was computed by applying the relative weights of each component
* Some of the questions have been revised and for the first time perceived consumer detriment from problems experienced has been surveyed
* a new weighting procedure has been introduced which incorporates more information than in previous waves; population figures per country  representing age, gender and phone type ownership. 
Therefore differences between 2017 and previous years are in this database presented on a separate sheet and they have been calculated using comparable weighting methods i.e. usually by applying the methodology of the previous wave. 
Since not the same sets of markets are surveyed in each wave of the survey the published differences are available for various comparison years (for example 2017-2015 and 2017-2013). 

Additional information 
Weights are used when aggregating to EU-averages (eg. country size by number of inhabitants). In addition, data from 2012 and onwards are weighted to reflect age and gender distribution of the population in the countries covered.
