Lehighton Chalk Company manufactures sidewalk chalk, which it sells online by the box at $24 per unit.

Timing is the key in distinguishing between absorption and variable costing.

Since Lehighton's combined operating income, across the two-year period, is the same under both absorption and variable costing, then the operating income must be the same within each year under both methods.

The difference between absorption and varible costing is caused by the timing with which expenses are recognized.