同比 / 环比【tóngbǐ / huánbǐ】

同比 and 环比 sit before a verb of change – 增长, 上升, 下降, 减少 – and say what the figure is measured against. The amount follows the verb, as a percentage or with 成 "tenths". They belong to statistics, business news and reports.

同比 or 环比

同比 compares with the same period a year earlier: this March against last March. 环比 compares with the period immediately before: this March against February, this quarter against last quarter. The same figure can rise on one measure and fall on the other.

A report written for general readers often spells the comparison out with 与去年同期相比 "compared with the same period last year".

Mistakes

同比 and 环比 go before the verb, not after it. They already contain the comparison, so 比 + a time doesn't follow them.

• × 销售额增长同比12% → 销售额同比增长12%
• × 销售额同比去年增长12% → 销售额同比增长12% / 销售额比去年增长12%