What about doing a video that answers the man's question where you imagine yourself as a communist party member and you try and determine weather or not to build the railway through the mountain, or around it. And then explain how we determine whether or not your answer is correct without market prices? The correct answer will obviously be the least wasteful, most practical, and most affordable solution. But... without market prices, it's a fools errand. It's like if you bagged groceries and you asked me: Would you like paper or plastic? If I responded with a yes. You'd be lacking the necessary data in order to respond accordingly. That's the knowledge problem, there's no data to be had which makes the job an impossible feat.