National debt increases when:

Raising taxes during a deep recession would decrease disposable income for consumers and businesses, further reducing demand and exacerbating economic contraction. This policy would likely lead to lower consumer spending and investment, which is counterproductive in a time when economic stimulation is essential.

Raising the reserve ratio is a monetary policy tool that banks use to control the amount of money available for lending. While it may help control inflation, it would restrict the availability of credit during a recession, hampering economic recovery efforts. This approach does not directly address the need for increased government spending to stimulate the economy.

Increasing government spending injects funds into the economy, creating jobs and encouraging consumer spending. This approach directly addresses the issues of high unemployment and low demand, making it a cornerstone of effective fiscal policy during economic downturns.