I definitely agree, and any "lost sales" are clearly evident in future revenue data. Opportunity costs are factors in economic decisions, but writing them down

I definitely agree, and any "lost sales" are clearly evident in future revenue data. Opportunity costs are factors in economic decisions, but writing them down would be laughable. My point was that Microsoft probably had some revenue trajectory with slope X before the write-down, and experienced a new revenue trajectory with slope Y < X after the write-down. I'm curious about the area between the two lines.