There’s no formula to calculate overtourism. But there is one to solve it

Overtourism strains destinations, causing socioeconomic impacts. New tools like the ‘flow congruence index’ aim to restore balance in strained regions.

There is a paradox at the heart of tourism. Often seen as a driver of economic and cultural growth, it also carries within it the seeds of its own decline.

From the moment a destination opens to visitors, it begins to change, altered by the very presence of those it attracts.

Over time, this gradual transformation can lead to overtourism, where the psychological carrying capacity of a location is exceeded, causing the destination to lose its appeal.

Without a precise formula to measure this threshold, researchers have developed a tool, the “flow congruence index“, to assess the balance between tourist demand and a region’s ability to sustain it.

This method helps highlight where imbalances could lead to the decline of once-thriving tourist spots.

Tolerable impact before development

In the early phases of Butler’s tourism life cycle model — exploration and involvement — tourism impact remains minimal as long as visitor traces are contained.

However, the landscape soon started to change with the appearance of the first hotels and other infrastructure. Local residents begin to view tourism as a source of development, which shifts the existing social and economic order.

Traditional livelihoods, culture, and customs become reshaped to meet the demands of visitors. Waste management also becomes a concern, as seen in the Maldives, where an entire atoll has been repurposed as a landfill.

Such developments are unsustainable, clashing with the pristine conditions that initially fuelled tourism and economic growth in the region.

Stagnation and decline

At this point, despite appearances of limitless growth, the “virus” of tourism is already active. Butler argues that, after the stages of development and maturity, destinations enter stagnation.

Growth halts, and visitors become disillusioned as they sense the degradation. Without corrective measures, destinations slip into decline, with tourism dwindling to marginal levels.

When carrying capacity is breached

J-M. Mïossec offers a more detailed account of the saturation phase that precedes decline: transport networks cover the entire region, and the local population focuses entirely on serving tourists. Visitors begin to recognise the changes and find that the destination no longer meets their expectations.

This marks the point where the destination exceeds its carrying capacity—the point where the area can no longer sustain growth, and tourists are unwilling to tolerate overcrowding, deteriorating services, and overt commercialization of local customs.

Limits of psychological carrying capacity

There is no definitive formula for calculating the exact carrying capacity. It isn’t about the number of hotel beds, parking spaces, or access infrastructure.

Rather, it’s a psychological threshold, beyond which the “tourism ecosystem” loses balance, and visitors no longer experience the same appeal as they did before.

For instance, 1,000 tourists in Milan’s Piazza del Duomo might be acceptable — even desirable, given the urban setting. But 100 tourists on a mountain trail could feel overcrowded for those seeking peace and connection with nature.

So overtourism can be defined as the excessive crowding that distorts a destination beyond its carrying capacity, leading to visitor rejection.

Tourist redistribution

Overtourism also has significant socioeconomic repercussions. It drives up prices, reduces housing availability, and forces residents to move away due to the high costs.

The concentration of tourism in key destinations also marginalises other locations in the region, where attractions may exist but go unnoticed.

A redistribution of tourist flows could help alleviate overtourism, minimise the underuse of facilities during the off-season, and improve visitor satisfaction by reducing overcrowding.

The flow congruence index

While it is impossible to mathematically define a destination’s carrying capacity, it is possible to identify imbalances in tourist flows within a region — an early warning sign of saturation, stagnation, and potential decline.

In the absence of specific indicators, a new method has been proposed: the “flow congruence index“.

This index measures whether tourist demand (number of visitors) corresponds to a destination’s attractiveness, or whether it exceeds or falls short of the location’s sustainable capacity.

The case of northern Piedmont

To compare destinations, their attractiveness must first be assessed. This method was applied experimentally to the province of Verbano-Cusio-Ossola in northern Piedmont, a region with cultural, scenic, and climatic appeal in the Italian Alps.

After consultations with local operators and authorities, an attractiveness score was assigned to each of the area’s resources. This data was then compared with the annual tourist presence in each municipality using a formula.

By design, the reference average value is 1. Scores below this indicate destinations with attractive resources that fail to draw proportional tourist numbers (undertourism), while locations with scores above 1 attract more visitors than expected based on their attractiveness.

Although this formula does not pinpoint a specific carrying capacity limit, the flow congruence index can indicate where overcrowding could lead to overtourism and its negative consequences.

Redistributing tourism for sustainability

This type of map could provide a useful starting point to identify and address overcrowding and offer insights into how tourist flows might be more sustainably distributed across a region.

With effective policies from institutions and governments, these insights can be transformed into actionable strategies that limit overtourism in popular destinations while promoting lesser-known areas.

Regulations on visitor numbers, investment in infrastructure for off-peak destinations, and the promotion of alternative tourism experiences can ensure a balanced distribution of tourists, preserving cultural heritage and reducing environmental stress. In this way, policy measures can foster a more sustainable and equitable tourism industry.

Guido Lucarno is professor of tourism geography at Catholic University of Sacred Heart, Milan. He published numerous essays on enhancement of attractive resources within tourist regions and conducted various research projects on territorial development from a tourism perspective on behalf of Italian public and private entities, in collaboration with the UCSC.

Originally published under Creative Commons by 360info™.