Does anyone understand how the world works? If we consider this question to be about the certainty of knowledge behind policy making, then the answer is no. This is because economic theory is central to the governance of modern society, but these current theories cannot be proven. This means that knowledge of economics is not equivalent to that of science, engineering, or medicine. The difference is that scientific theories require proof, whereas current economic theories cannot be proven.
Unfortunately, as economic theories cannot be proven, they cannot be disproven either, so persuading policy makers of the need to change policy requires accumulating a vast amount of evidence. Indeed, we might consider rising child exploitation, loss of biodiversity and global warming to be such evidence, but they still deny this is due to their policies. Problematically, convincing policy makers of the need to change will lead us into catastrophe.
In contrast, if the knowledge of economics were equivalent to that of scientific disciplines, we could be proactive in establishing sustainable, equitable and stable economies. A new approach to economic forecasting is presented in the publications below. At its core are the philosophy of science and the mathematics of engineering. The new approach, called Economy Dynamics, is provable unlike any current theories of economics.