Costco has announced a wage increase for its employees as it faces the possibility of a strike by 18,000 unionized workers. Under the new agreement, senior staff will see their pay rise to over $30 per hour over the next three years, while entry-level wages will increase to $20 per hour. The move comes amid negotiations with the Teamsters union, which argues that the increases may not fully address worker demands. The union has authorized a strike if an agreement is not reached, potentially disrupting operations at Costco locations across the country.