What is the net worth assessment process used by the Finance Minister in determining income for a taxpayer?

In Ramey v. The Queen, 93 DTC 791 (T.C.C.), Bowman T.C.C.J. at page 793 described the net worth process as follows: ... The net worth method of estimating income is an unsatisfactory and imprecise way of determining a taxpayer's income for the year. It is a blunt instrument of which the Minister must avail himself as a last resort. A net worth assessment involves a comparison of a taxpayer's net worth, i.e., the cost of his assets less his liabilities, at the beginning of a year, with his net worth at the end of the year. To the difference so determined there are added his expenditures in the year. The resulting figure is assumed to be his income unless the taxpayer establishes the contrary. Such assessments may be inaccurate within a range of indeterminate magnitude but unless they are shown to be wrong they stand. It is almost impossible to challenge such assessments piecemeal. …