Phil gets the house to himself for a few days and he’s opted to upgrade the technology in the home. He programs everything in the house to be controlled by his iPad, essentially freeing himself to do other tasks that require his attention. He can now turn on lights, the TV, and the fireplace from his device. Long term growth in economies is often fueled by capital investments, which allows populations to be more productive. The same is true at the household level, such that investments in capital improve the productivity of inhabitants.