Arms around MacroEconomics

I have been revising my understanding of macroeconomics from the explosion far away to a more manageable issue or set of issues. Heres my first skinny on it

1. The Economy has 2 primary categories of actors consumers and suppliers
2. The economy runs on the basic principle of supply and demand
3. Overall measuring supply and demand is impossible and so statistical means are used therefore we have somethign called aggregate demand and aggregate supply
a. Y=C+S+T (all that you make can be consumed or saved or paid in taxes)
b. Y=C+I+G+(X-M) (all expenses by consumers, investments, governemnts and cros border trade also amount to overall product)
c. Growth in Y is not unlimited and dependent on a variety of factors.
d. All actions result in an opposite reaction(of lower magnitude)
4. Economies chug along on business cycles, i.e. there will be booms and busts.


Then there are details :-)