 What we mean by elasticity of scale is actually related to the returns to scale. In returns to scale we have studied that when there will be the total increase in the amount of the inputs or all the inputs there are scaled up or scaled down then what will be the impact in the total amount of the output. So keeping in view now that returns to scale we are going to measure the proportionate change in the output due to change in that scale. So proportionate change in the output y due to proportionate change in the scale is called elasticity of scale and if we show here that is this change in y due to y will be equal to change in the output and when it is divided by change in scale due to that that will be proportionate change in scale. So when this change in y by y is divided by change in s by s so we invert this and it comes like this s by ds and it is explained here. So proportionate change in the output due to change in the scale will be called elasticity of scale and coming to this now we say that what is the basic significance for this. We want to assess here that either change in the inputs or the scaling has caused in the output change more than a certain point or less than that certain point. So that either that change or the scaling was feasible or it was beneficial that and to want to decide that if he is enhancing the amount of his inputs, increasing all of them, then is there really an increase in the output and either that increase is as much as it is required or the input is above it. So if the amount of the input increases, the more the output increases, then we will say that at least there was no loss. But this is also a possibility that on all the inputs, we say that the scaling is going up and increasing, but the output is decreasing in the output. So here the entrepreneur has to see one thing, the main thing is that the output is increasing but the output is not increasing in the output of that output. But if we look at the overall society, then we have to see it here as in the planning setup, because all the capital and resources that the entrepreneur or the producer uses and if the output is not increased, then there is an opportunity cost for them who have to pay the society and who have to pay it themselves, then those inputs, they can be utilized at any other place in a better way. So from here our concept of opportunity cost is also developed. And from here, if we look at the aspect of externalities on our environmental aspect, that along with all these things, that is supporting our society in a better form or giving negative conditions there. So that is why when elasticity of scale is looking at our resource saving, our efficiency setup and our welfare aspects, its study is very important. Now if we look at it graphically, then in front of us, there are three kinds of isoquants shown here and if we look at these three isoquants, then there are various combinations of inputs between which there is possibility of switching. Now if we look here, then these straight lines from origin are basically joining these three points over these three isoquants and they actually show those combinations where if we bring these three together, then it means it shows the constant returns along this OB line and at the same time this shows the constant returns along this OA line. So these are the combinations where the more inputs are increased, then here this particular point is also increasing in the output at that point. And if we look at it in this form, then by expressing these three points, we say that this is constant returns along our show. Now similarly, the possibility is that instead of constant, our actual whenever it is, the possibility is that this is not constant or the amount of input scaling done in the output proportionate change is more or less than that. So the three forms of returns to scale that are coming in front of us will be clearly explained. Now if we look at the output, the amount of input done by scale, if it is more or less or equal, then we will have either increasing returns to scale or constant returns to scale or decreasing returns to scale. So it is possible that whatever combination we have in all these forms, when we explain it, then this will explain what we have earlier. So this will be when we can say there are the increasing returns to scale, that we are enhancing the inputs, but the output that is increasing in the output of enhancing the inputs is also increasing. Now if we look at it here, then the increase is a vertical show. But if we look at it along with the vertical show, then if we look at the slope, then this slope is also showing us that it is increasing. Means if we take its first derivative, then it is also showing its curvature in the increasing rate form. In the second form, if we look at the proportionate change, then when we explain the elasticity, then it will show us that there is a straight line. Change in the output due to change in the total scaling will be equal to the straight line or the same. So this is our constant returns to scale. Now similarly, if we look at another graph, then it is showing us upward. But this upward line, but upward decreasing means that is increase in output at decreasing rate. So this will be decreasing returns to scale in front of us. When this is our less than one equation. Now here possibility can be that it is not necessary that from the start onwards, either same increasing rate of return or constant or decreasing, there is a possibility that the change of production function will change shape or curvature. So this is possible in this form. If we go to this part, then there is a point of inflection coming up to that point of inflection. This was increasing at increasing rate. And after this point, it was decreasing at decreasing rate. So initially increasing rate and after that it is decreasing. And similarly, we see that we can draw one more which can be that initially it is increasing and afterwards it takes the shape of decreasing. So this can be a shape like that. So there is a possibility in which we can say that this elasticity of scale may vary from one aspect to other aspect. Thank you. .