A counter-example to the Stolper-Samuelson theorem has firms using more skilled labor as it becomes more expensive, and less unskilled labor as it become less expensive, even if the firms have time to adjust their labor mix. How can this possibly be?

Doogan corporation makes a product with the following standard costs: standard quantity or hours standard price or rate direct materials 2.0 grams $ 7.00 per gram direct labor 1.6 hours $ 12.00 per hour variable overhead 1.6 hours $ 6.00 per hour the company produced 5,000 units in january using 10,340 grams of direct material and 2,320 direct labor-hours. during the month, the company purchased 10,910 grams of the direct material at $7.30 per gram. the actual direct labor rate was $12.85 per hour and the actual variable overhead rate was $5.80 per hour. the company applies variable overhead on the basis of direct labor-hours. the direct materials purchases variance is computed when the materials are purchased. the materials quantity variance for january is: