Excessive tourism, or the increase in the number of tourists towards a saturation level, is evidenced by: diversion of land to the accommodation of tourist facilities, thus preventing its use for houses, schools and open space; threat to the local employment structure by the growth of seasonal and low-paid employment needed to service the tourist industry; and pressure on the general urban infrastructure, particularly transportation, through the steadily increasing (although seasonal) tourist flow. These factors alienate local residents, particularly when the tourist facilities consist primarily of casinos and strip-shows which attract crime and prostitution. Deterioration of tourist areas is usually progressive, involving misuse of resources and spoilage of the very assets that brought the tourists in the first place. Overdevelopment drives tourists away to the next popular and unspoilt location. Social problems often accompany the growth of tourism, including: social friction arising from the importation of foreign workers; confrontation such that the better-off traveller gives orders to the less-well-off native; resentment of residents having to share services with tourists; disappearance or commercialization of local cultures and customs leading to a monotonous world non-culture of identical styles, behaviour patterns, entertainment, food, and language. Economic problems include: hindrance to the growth of a country's economy through the commitment of a large portion of the labour force to a service activity with poor productivity prospects; inflationary consequences of excessive tourist activity, in particular enormous increases in the price of basic foodstuffs and other commodities required by both the tourists and the local population; unfavourable impact on the balance of payments due to the initial investment, imports for maintenance and outward movement of profits; heavy infrastructure costs; loss of control over the economy due to the absence of fiscal regulators where taxes are low or non-existent in order to encourage foreign investment; and overdependence of an economy on one product vulnerable to changes of fashion.
Tourism has a highly complex impact on cultural values. Tourism activities may lead to inter-generational conflicts through changing aspirations of younger members of communities who may have more contact with, and are more likely to be affected by, the behaviour of tourists. Furthermore, they may affect gender relationships through, for example, offering different employment opportunities to men and women. Traditional practices and events may also be influenced by the tourist preferences. This may lead to erosion of traditional practices, including cultural erosion and disruption of traditional lifestyles. Additionally, tourism development can lead to the loss of access by indigenous and local communities to their land and resources as well as sacred sites, which are integral to the maintenance of traditional knowledge systems and traditional lifestyles.
In 1971, 181 million tourists spent $19,900 million (excluding payments for international transportation). In 1990, international tourism counted 415 million people, $230 billion in turnover, and a rating as one of the fastest growing industries in the world and the third largest export industry after oil and oil products, and automobiles.
Only 12 countries account for 75% of all tourists, and two of these (USA and Germany) account for 40% of all tourist arrivals, although they represent less than 10% of the world's population. The problem will considerably increase when incomes rise sufficiently in other areas of the world to permit international travel.
The Caribbean government of St Lucia used US$ 174 million, or 11.5% of its gross national product in 1992, in tourism development. Visitation to the Caribbean by American tourists has fallen since 1990, where environmental problems (harassment from islanders offering sex and drugs, deteriorating appearance of infrastructure and the natural environment) are now regarded as a threat to the tourism industry. Some hoteliers have turned their properties into "all-inclusive resorts" – walled to exclude the locals and patrolled by security guards.
The number of international tourists to China has increased by five-fold in the period from 1980 to 1990 and shows typical indications of the social impact of tourism. One reported effect has been preferential occupation of scenic locations for tourism facilities and the displacement of farmers to build golf courses. Discos and rock bands are gradually taking over the opera, national dances and folk music, and some traditional arts and handcrafts are losing their original style. Prostitution has become one of the main social problems in Hainan province, one of China's Special Economic Zones, where in 1991, 24 out of 28 restaurants in the capital were serving endangered species on the menu; and drug taking and selling is spreading in Yunnan province.