17 Hours per Adult
A healthy economy is one that is constantly growing when looked at on an annual basis (each year bigger than last) and this constant growth comes from entrepreneurs exercising their freedom to innovate in the absence of government regulations.
An unhealthy economy is one that doesn't constantly grow every year (each year not necessarily bigger than last). This is because there is structural rigidity when there is a government-regulated economy.
There is no authorization in the US Constitution for the government to be regulating the economy (it's not a legitimate federal power) and America's first century involved near-total economic freedom.
Enter FDR
However, in just 4 years from 1937-1941, FDR appointed seven new Supreme Court Justices--each willing to tow the party line for FDR's socialist, New Deal policies (eg. Wickard v. Filburn, 1942), making America economically unfree from that point forward.
The US constitution began to be interpreted differently by the Supreme Court than it had been previously, and this opposite interpretation of what it says is seen as early as 1937 (West Coast Hotel v. Parrish)--when FDR had threatened to "pack the court" with seven good-ole'-boy justices of his choosing, bringing the total to 16 justices.
Justice Roberts in 1937 switched sides so as to decide the Supreme Court case so that FDR would get the Supreme Court ruling that he personally wanted to get ("the switch in time that saved nine").
Healthy Economies
A sweetspot exists with regard to how much work people want: 17 hours per week in the private sector. It's not 17 hours for each and every person (different people want different amounts)--it's just 17 hours on average.
If the economy is healthy, adults work an average of 17 hours in the private sector, making tons of money (families are all well-supported and able to afford family vacations, etc.).
In fact, 1979 was the first year that a per-adult average of more than 17 hours of work per week was required to support a family at high living standards (previous years had allowed for less total work, but with more growth in living standards):
But what about unhealthy economies?
Unhealthy Economies
In unhealthy economies, people work more than 17 hours on average*--until a shock hits which disrupts the rigid regulatory structure of unhealthy (unfree) economies.
--------
*Note: These new workers working more than 17 hours (in the unhealthy economy) don't make good pay like the workers of the healthy economy did above--which explains why they need to work more to make ends meet.
--------
Then, as the shock hits, the nation with an unhealthy economy is driven into deep recession, and much less than 17 hours are available--even at low pay compared to free economies.
Because of prior government intervention (mitigated adaptability to shocks), the US is having an economic crisis and we have apparently lost 36 million jobs in 8 weeks--leaving 13 hours of work available per US adult (one full-time job in the private sector for every 3 adults in America).
A Sustainable Way Forward
To prevent this type of thing from recurring, it is necessary to shrink the federal government in both its size and its scope of operations.
There are now less than 1.5 full-time equivalent jobs in the private sector (where wealth is created) per social security beneficiary, so economic freedom will be the only way forward.
You cannot tax your way forward, you cannot spend your way forward with stimulus plans. And you cannot inflate your way to prosperity. The only way forward is the freedom of self-governance which we all had in the last half of the 1800s.
Sources
U.S. Bureau of Economic Analysis, Full-time equivalent employees: Domestic private industries [A4303C0A173NBEA], retrieved from FRED, Federal Reserve Bank of St. Louis
U.S. Bureau of Labor Statistics, Population Level [CNP16OV], retrieved from FRED, Federal Reserve Bank of St. Louis