Economics: an approximation

Economics is good at pursuing a way to explain phenomenon in the real world and captures some basic "economic" rules in our life; however, economics can never precisely describe the entire picture of the world. For example, economics is about how individuals make decisions based on profits (utility) and costs, when economics come to individual cases, it is hard for any economist to find a general and direct method to calculate the marginal cost, which is an extremely concept in economic theories studying firms' strategies. Moreover, when economists are talking about utility, utility is significantly dependent of individual tastes, different individuals can have different utility, economists tend to use a mean individual to represent the entire population, but it is just not possible to be sure if a right mean individual is found.

Secondly, economics describes the current situation based on economists' expectations of the future and does not deliver the prophecy. Economists tend to think individuals and the economic system behave or function in a typical cycle or following certain rules. No one knows the future, so based on several assumptions that create a stable and reasonable system, economists form some expectations of the future and create models based on these expectations. Furthermore, when economists tend to make predictions, they also bring the idea of stability from the models to the reality, by projecting a trend, they make their predictions along this trend which comes from their models.

Thirdly, economics is not natural science, though it tends to be mathematical and data-intensive. Because economics studies social issues that largely involves numbers, economists tend to bring in the concepts of experimental science, statistics and mathematics. The findings do not come from the nature, they come from the interaction between individuals and such interaction can change over time.