Rejection Cost. From the perspective that my profit is someone else’s loss, and someone else’s profit is my loss, the fact that I have to reject an opportunity to make money for my circumstances is a loss for me and an act of giving someone else a profit. In other words, my added value is not determined solely by productivity but also by the marginal utility generated by the law of supply and demand. Therefore, my labor price should reflect the value that I have given up—the profit I could have gained. If the rejection cost is not included in my profit, I will be at a loss to that extent. Failing to account for rejection costs in production expenses is not wise, but foolish, because it risks my survival. There is no absolute value in this world. All economic values are relative. - Joseph’s “just my thoughts”
Even though a country's total population is decreasing, the economic situation could be improved by increasing the total economic activity of the remaining population after the decrease. Of course, there is a statistical population threshold below which this effect occurs. Nevertheless, this effect would not work in the case of a force majeure, such as a natural disaster or the outbreak of war, however, this assumption would be valid because a rapid population decline is a highly exceptional event that would not normally occur. Therefore, an increase in the economic activity of this population should be required during an economic recession. Applying this perspective, for building a solid relationship with your followers on Instagram, the number of followers is less important than the activity between them and you. This is called the "Engagement Rate (ER)". - Joseph’s “just my thoughts”