Final answer:
Demand savings accounts have proliferated due to their secure nature and accessibility for savers, their role in economic growth through loans, and the influence of financial security planning and policies like Social Security on saving behaviors.
Step-by-step explanation:
The drivers behind the proliferation of demand savings accounts are multifaceted. Primarily, these accounts are popular because they provide a secure place for households and businesses to store their savings with easy access when needed. This money can then be used by banks to offer loans to individuals and businesses, which fuels economic growth.
Another driver is the planning for long-term financial security, such as retirement, where current income exceeds immediate needs and prompts saving. Lastly, financial policies like Social Security can influence savings rates by providing future financial support, thereby affecting how much people save.