If money income stays the same, but the price of one good goes up, the effective purchasing power falls, and vice versa.
Purchasing power is linked with Inflation.
... 200s 210s 220s 230s - 240s - 250s 260s 270s 280s 290s Years: 237 238 239 240 241 - 242 - 243 244 245 246 247 Events Patriarch Titus[?] succeeds Patriarch Eugenius ...