By Matthew Berg
The central insight of the sectoral balances model of the economy is that not all sectors of the economy can net-save at the same time. That means that if all those of us in the private sector in aggregate want to (on net) take in more money than we spend, then some other sector will have to spend more money than it receives. In a simple three sector version, the three sectors are the domestic private sector, the government sector, and the foreign sector.