What are the best ways to account for seasonal variation in economic data?
Seasonal variation is the regular and predictable change in economic data that occurs due to the influence of factors such as weather, holidays, festivals, or agricultural cycles. For example, retail sales tend to increase in December due to Christmas shopping, while unemployment tends to rise in January due to seasonal layoffs. Seasonal variation can obscure the underlying trends and patterns in economic data, making it difficult to compare data across different periods or to identify the effects of other factors such as policy changes, shocks, or structural shifts. Therefore, economists often use various methods to account for seasonal variation and to obtain seasonally adjusted data that reflect the true state of the economy.