How will wage negotiations work in a world on the bitcoin standard

In a world on hard money (like bitcoin) that steadily appreciates in value as the global economy grows, it would be necessary to periodically reduce wages slightly to maintain their value. How would people adapt (psychologicaly) from having a world where they were used to wage increases, to getting used to wage decreases each year (even though the purchasing power of the wage will remain constant)? Also, how would employers know by what amount to reduce wages to keep purchasing power the same?