L'Aran and a total of 22 counties registered seasonal population increases in 2016, while the remaining 19 counties registered seasonal population decreases, according to the Seasonal Population Estimates. In absolute terms, El Tarragonès was the county with the highest seasonal population (44,317 people AFTE), followed by El Barcelonès (39,483) and El Baix Empordà (27,635). At the other extreme, among the counties with seasonal population decreases, El Baix Llobregat (&minus32,832 persons AFTE) and El Vallès Occidental (&minus19,349) stood out particularly.
El Pallars Sobirà (29.1%), Aran (25.3%), El Baix Empordà (20.8%) and La Cerdanya (19.7%) were the counties with the highest seasonal population in relative terms. Conversely, 19 counties registered seasonal population decreases, but in all cases, the population decrease was less than 5% of the registered population.
Of the 220 municipalities which provided results for 2016, 88 of them registered an increase in seasonal population. In absolute terms, besides Barcelona (which is the municipality in Catalonia with the largest seasonal population, with 85,729 people AFTE), Salou (23,305) and Lloret de Mar (16,941) stood out. In relative terms, Santa Susanna is worth mentioning because its seasonal population is estimated to be 175.0% of its registered population. Then come Salou and Tossa de Mar, which registered an increase over their resident population ranging from 88.3% and 86.5%.
Idescat has incorporated improvements into the Seasonal Population Estimates and has established a new base (2016) which incorporates information derived from new statistics, primarily from those of Tourist Movement. With the aim of facilitating the comparability of data from 2016, Idescat has revised Estimates from 2015, in accordance with the criteria of this new 2016 base.
The seasonal population estimates constitute an estimation of the population burdens supported by each municipality and measure the number of people there are in a municipality as a yearly average and a quarterly average. The calculation includes people that have some sort of association or relation with the municipality, whether that is because they reside there, work there, study there or despite not having their regular residence there, spend some period of time there (holidays, summer breaks, weekends, etc.), either in their own homes or in those of friends and family or in tourist establishments (hotels, campsites, apartments, etc.). Given the complexity of estimating non-obligatory movement involving no overnight stays, this has not been considered.
The measurement unit for seasonal population estimates are annual full time equivalents. Every day that a person is present in a municipality equates to 1/365 annual full time equivalents (AFTE). So, for example, a person who spends a week's holiday in a municipality equates to 0.02 AFTE.
The AFTE seasonal population or annual full time equivalent seasonal population is defined by the result of the balance between entries of population not resident in the municipality and exits of population resident in the municipality, measured as an annual average number of people per day.
AFTE seasonal population = AFTE non resident population present – AFTE resident population absent
Idescat published annually The seasonal population estimates are designed as a synthesised statistical activity that collects information from different sources, such as municipal population registers, population censuses, tourism statistics, employment statistics, education statistics, and statistics on the population's quality of life and habits.