Half the counties registered seasonal population increases in 2017, according to the Seasonal Population Estimates. In absolute terms, El Tarragonès was the county which registered the highest seasonal population, with 47,721 people AFTE (annual full-time equivalent population), followed by El Barcelonès, with 36,842 people AFTE. At the other extreme, the counties with seasonal population decreases included El Baix Llobregat (−33,791 persons AFTE) and El Vallès Occidental (−20,085 AFTE).
In relation to the previous year, El Baix Empordà, El Tarragonès and L’Alt Empordà were the counties where the seasonal population increased most in absolute terms (by 4,061, 3,404 and 3,203 people AFTE respectively). In contrast, the county where the seasonal population decreased most was El Barcelonès (−2,641 people AFTE).
Salou was the municipality where the seasonal population figure increased most in 2017 (2,507 people AFTE), totalling 25,812 AFTE. In contrast, the municipality where the seasonal population decreased most was Lloret de Mar (&minus1,001 people AFTE).
Of the 220 municipalities which provided results for 2017, 91 of them registered seasonal population increases. In absolute terms, besides Barcelona (the municipality in Catalonia with the highest seasonal population, with 85,113 people AFTE), we should highlight Salou (25,812) and Lloret de Mar (15,940).
In relative terms, we should mention Santa Susanna, where the seasonal population was equivalent to 174.3% of the municipality’s registered population. It was followed by Pals (108.9%), Salou (98.4%) and Tossa de Mar (90.9%).
The Seasonal Population Estimates are statistical operations consisting of an estimate of the population influxes borne by each municipality. They measure the mean number of people in a municipality on an annual and quarterly basis. The calculation includes people who have some kind of relationship with the municipality, whether it be because they work, study or have passed a period of time there. Given the complexity of estimating non-compulsory mobility without overnight stays, it was not taken into consideration.
The unit of measurement used to calculate the seasonal population estimates was the annual full-time equivalent population. Each day a person is present in a municipality is equivalent to 1/365 of the annual full-time equivalent population (AFTE). Thus, for example, a person who spends a weeks’ holiday in a municipality is equivalent to 0.02 people AFTE.
The seasonal population AFTE or annual full-time equivalent population is defined as the balance resulting from the inflows of the non-resident population and the outflows of the population residing in the municipality, measured in terms of an annual average of people per day.
Seasonal population AFTE = non-resident population present AFTE - resident population absent AFTE
Idescat annually draws up the Seasonal Population Estimates from various sources, such as municipal registrations of inhabitants, the Population Census, statistics on tourism, labour statistics, education-based statistics and statistics on living conditions and population habits. The data is presented by 41 counties and Aran, for municipalities of over 5,000 inhabitants (either the registered population or the annual full-time equivalent population or AFTE) and also for county seats.