Suppose that investment demand increases by $300 billion in a closed and private economy (no government or foreign trade). Assume further that households have a marginal propensity to consume of 80 percent. Ultimately, how much will aggregate demand increase? Enter your answer in billions. For example if your answer is $600 billion then enter 600. If your answer is $1,500 then enter 1500.

Aggregate demand increase by $1500 billion.

Answer is 1500

Explanation:

Investment demand increases by $300 billion.

MPC = 0.80

Multiplier = 1 / (1-MPC)

Multiplier = 1 / (1-0.8)

Multiplier = 1 / 0.2

Multiplier = 5

Multiplier = Change in GDP / Change in investment

5 = Change in GDP / $300 billion

Change in GDP = 5 * $300 billion

Change in GDP = $1500 billion.

cognitive overload: having a lot on your mind impairs decision-making and tends to result in the simplest, but not necessarily best, option being selected.

empathy gaps: overlooking how you might feel in a different situation can result in unnecessary purchases, such as overbuying when shopping for food on an empty stomach.

optimism and overconfidence: wearing rose-tinted glasses and having unrealistic expectations about the future can affect money management and leave you unprepared for a change in circumstance.

instant gratification: seeking instant gratification drives impulsive spending and can undermine long-term planning and savings.

harmful habits: automatic or mindless behaviour can amplify a poor financial decision as it becomes a recurring event.

social norms: we are heavily influenced by the actions of others; while this can be in certain circumstances, it also contributes to the pressure to keep up with the joneses through conspicuous consumption.