Why a diagram?
As a student one studies the phenomena of each science more or less separately.
Take, for example, the phenomenon of wage increases in economics. The causes of an increase in wages (inflation, wage demands, ..) and its consequences (higher production costs, increasing consumption …) are analyzed. But rarely influences on other economic fields, such as the exchange rate are dealt with.
Could you spontaneously describe the influence of wage increase on the exchange rate of national currency?
Here are some possible reasonings:
If wages rise, production costs increase.
If production costs rise, prices rise.
If prices rise, exports drop and imports rise.
The decrease in exports reduces the demand for national currency and the value of money decreases.
The rise in imports leads to an increase in the supply of domestic currency and also lowers its value.
There are, of course, many other links and influences. However, a text to describe them would be very long and the reader would soon lose the overview.
Hence the idea of presenting the links and influences in a schematic diagram containing “all” economic concepts and showing their influences on each other.
The initial idea was to represent those links in a three-dimensional space, but after a few months of work, it turned out that two dimensions were sufficient, especially as this made reading the representation much easier.