Final answer:
Variations in tourism demand can be attributed to economic, political, social, and technological factors, which can also cause shifts in the demand curve for goods and services.
Step-by-step explanation:
The reasons for the variation in levels of demand in tourism often reflect a combination of different factors. The key aspects influencing this variation can be categorized into economic factors, such as fluctuations in income levels and pricing, political factors, including changes in travel policies or political stability, social factors, like shifts in consumer preferences or demographic changes, and technological factors, which can affect the ease and cost of travel.
Additionally, understanding the shift in the demand curve in markets for goods and services involves analyzing demand factors to determine whether an economic change affects demand or supply. An example of this analysis can be seen through the impact of economic factors such as deindustrialization or the rise of communication technologies on political party decline.