Financial assets are set to make up more and more of the Crown's balance sheet. The Crown's net worth fell by $37 billion between 2008 and 2013.
That's largely because of increased borrowings, a rise in insurance liabilities due to growth in the ACC scheme and the Canterbury earthquakes, and higher retirement liabilities.
At the end of June last year, the Crown's assets totalled 244.4 billion dollars, while liabilities stood at 174.4 billion dollars.
Treasury says it is preparing for the aging population and the composition of the Crown's assets will change.
Financial assets, such as the New Zealand Superannuation Fund and ACC's fund portfolio are projected to constitute well over 600 billion dollars, or 45 percent of economic growth, in 2057/58.
Treasury is forecasting that the total net worth of the Crown will grow by 28.2 billion dollars over the next five years to 92.3 billion driven by operating surpluses and revaluations to financial assets.
By 2018 assets are forecast to increase by 14.5 percent to 279.9 billion, while liabilities are expected to rise by 4 percent to 181.6 billion.