Assume Southern Copper Corporation (SCCO) acquired mining equipment for $100,000 cash on January 1, 2018. The equipment had an expected useful life of four years and zero salvage value. SCCO calculates depreciation using the straight-line method over the remaining expected useful life. On December 31, 2018, the market value of the equipment is $81,000. The expected useful life does not change. On December 31, 2019, after recognizing depreciation for the year, SCCO learns that new equipment now offered on the market makes the purchased equipment partially obsolete. The market value of the equipment on December 31, 2019, reflecting this obsolescence, is $46,000. On December 31, 2020, the market value of the equipment is $23,000. SCCO sells the equipment on January 1, 2021, for $26,000. Ignore income taxes.