According to Ray Dalio, whose lecture was recommended by Honey Panda, the three economy forces include productivity growth, short term debt cycle (5-8 years), long term debt cycle (50-75 years).
In a nutshell:
- total spending = $ + credit
- price = total spending / total quantity 
- Central government: collects taxes + spend $
- Central bank: prints $ + influences interest rate
- $ is only to increase productivity
- our spending is another person’s income
- credit and debt are of similar concept, just that credit is an asset to lender, debt is a liability to borrower
- income ↑, borrowing ↑, spending ↑
- borrowing (credit) create cycles. In cycles, after move upward, must move downward
- inflation is due to spending ↑ faster than quantity ↑
- inflation increases interest rate
- In a recession, lowering interest rates works to stimulate borrowing.
- In a deleveraging, lowering interest rates does not work.
- If deleveraging, how? cut spending + reduce debt + redistribute wealth + central bank prints $
- recession →deleveraging →depression
- If depression, how? debt restructuring, increases tax
- 3 rules of thumb: (1) don’t have debt ↑ faster than income , (2) don’t have income ↑ faster than productivity (so that we don’t end up being uncompetitive), (3) do all that we can to ↑ productivity.
 Since credits have been easy to obtain, they increase total spending and hence prices for e.g. property. See also ref2016/ray_dalio_economy_20160705.pdf
 If debt ↑ faster than income, debt burden will crash us.