To the right, we show three possible production choices facing this small firm. It could choose to produce at point A, turning out 9 Style 1 chairs and 3 Style 2 chairs. Or, it could choose B where it produces 6 chairs of each style, or C where it makes 3 Style 1 chairs and 9 Style 2 chairs. It can choose any combination of 12 chairs, including producing 12 a day of only one style.22 This firm's PPF for oak chairs is a straight line with a slope of -1. The PPF is linear because the opportunity cost of Style 1 chairs in terms of Style 2 chairs is constant.
22 The unbroken line we use for the PPF suggests that the firm can make chairs in fractional quantities. This is actually quite reasonable. In a 10 day period the firm can choose to produce 95 Style 1 chairs and 25 Style 2 chairs, or 9.5 and 2.5 per day, so every point on the PPF is feasible.