Final answer:
In the computation of GDP, the purchase of shares in a mutual fund is not considered private investment, as it does not pertain to the creation of new physical assets but to the transfer of existing financial assets.
Step-by-step explanation:
The item that would NOT be a part of private investment in the computation of GDP is the purchase of shares in a mutual fund. The Gross Domestic Product (GDP) measures the value of economic activity within a country. Private investment as a component of GDP includes the construction of a new factory, investment in research and development, and building a new residence. These are physical investments that represent current economic activity and contribute to future production capabilities.
However, purchasing shares in a mutual fund does not constitute investment in the GDP sense because it involves the transfer of ownership of financial assets rather than the creation of new physical assets. Investment expenditure in national accounting refers to spending on new capital goods, such as producer's durable equipment, nonresidential and residential structures, and changes in inventories.