Trend Systematic Overall or persistent, long term upward or downward pattern of movement Changes in technology, populations, wealth. Value Several Years

Seasonal Systematic Fairly regular periodic fluctuations that occur within each 12-month period year after year Weather conditions, social customs, religious customs Within 12 months

Cyclical Systematic Repeating up and down swings or movements through four phases: from peak (prosperity) to contractions (recession) to trough (depression) to expansion (recovery or growth) Interactions of the numerous factors that influence the economy Usually 2-10 years with differing intensity for the cycles

Irregular Unsystematic The erratic or residual fluctuations in a series that exist after taking into account the systematic effects Random variations in data or due to unforeseen events such as strikes, hurricanes, and floods Short duration and non-repeating