What is a Decline-in-Value Assessment? In 1978, California voters passed Proposition 8 which allows for a temporary reduction in assessed value when a property experiences a decline in value. These temporary value reductions are applied to properties when the total assessed value is greater than the current market value as of January 1st. Under state law, county assessors must enroll the lesser of a property’s adjusted base-year value (Proposition 13 value) or its current market value. Conversely, under state law, as market conditions improve and a property’s market value increases, assessors must “restore” the assessed value back to the adjusted base-year value. As a result of a strong recovery in the residential real estate market, this year’s decline-in-value review included significantly more restorations of assessed value. 15