増減

1. Origins, structure, and basic meaning

• Structure: 増減(ぞうげん) covers changes in quantity in either direction: increase or decrease.
• Basic usage: It describes tourist numbers increasing and decreasing with the seasons.
  • 季節によって観光客の数が大きく増減する。

2. Common pitfalls and similar expressions

• Not limited to increases
  • 増加(ぞうか) indicates an increase, and 減少(げんしょう) a decrease. 増減 covers changes in both directions.
• Fluctuations and comparisons
  • It can describe fluctuations, as in 季節による増減, or a difference between two points in time, as in 前月からの増減. Repeated cycles of increase and decrease are not required.