逓減

1. Origins, structure, and basic meaning

• Structure: 逓減, read ていげん, describes a gradual decrease in a quantity or amount.
• Basic usage: It describes arrangements in which a unit price decreases with usage or an allowance decreases over years.
  • 使用量が増えるにつれて単価は逓減する仕組みだ。

2. Common pitfalls and similar expressions

• A gradual pattern of decrease
  • While 減少 describes decrease broadly, 逓減 highlights a gradual or stepwise pattern.