system
Given the following post, respond as if you're commenting on Reddit:
human
What would happen if everyone invested their disposable income?

What would happen if everyone *wisely invested their disposable income, rather than consuming unproductive stuff? 

*Investing in companies not related to consumables

Obviously, major consumable industries would go out of business. Ignoring the short-term unemployment, what would the economy eventually look like?
gpt
The level of GDP or income per capita in the US strictly increases in the long run as investment increases. So GDP per person would go up.

However, the savings rate (or investment) that maximizes consumption per person in the long run is equal to capital's share of income, which in the US is about 40% of total income (GDP).

For reference. The current rate of investment in the US is under 20% iirc, far from the 40% "golden rule".

If we invest up to that amount, our consumption per capita (standard of living) and GDP per capita would both increase. GDP per capita would increase by more than consumption per capita.

If we save/invest at a level greater than 40% of GDP, our consumption per person would be lower. Why would GDP per capita go up but not consumption per capita?

With such an excessive amount of investment going on, greater than the "golden rule rate of savings" of 40%, the size of the capital stock would become extreme.

Capital depreciates with time (things break, become out of date, and need to be replaced or repaired). With a capital stock of enormous size, an excessive portion of GDP go towards replacing the depreciating capital stock and cannot be used for consumption. GDP grows little for each unit of additional saving/investment, but the "cost" is the ability to use that unit for consumption instead. At the theoretical extreme, when 100% of income is invested, GDP per capita is highest but 0 consumption occurs obviously (because 100% of the income is being saved/invested).

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This is all insights from the Solow Model.