Is Wage expense an account that is used for wages earned but not yet paid?

When using the accrual method of accounting, expenses are recognized when they're incurred, rather than when they are paid. Consequently, wage expense (or almost any expense, for that matter) is recognized in the period during which it was incurred, in this case, when it was earned by the employee.

Depending on the manner in which people are paid, on any given balance sheet date (usually the last day of each month), there may be wages earned, but which won't be paid until the beginning of the next month, i.e. the next pay date. Therefore, at the end of the month, we "accrue" the unpaid wages to recognize the expense incurred. This ensures the expense is reported in the proper period.

A similar concept applies to revenues using the accrual basis of accounting.