The core of this debate is to point out the limitations of the 'income source theory' adopted by the current income tax system and to argue that it should be converted to the 'net asset increase theory'. The income source theory takes the approach of taxing only the income listed in the law, which reveals obvious limitations in capturing all the various newly emerging capital incomes in a rapidly changing economic environment. On the other hand, the net asset growth theory considers the total increase in the value of assets held by a taxpayer over a specific period as an improvement in economic ability and defines this as income. Experts emphasize that this shift in perspective is a theoretically superior alternative that can increase tax fairness and fill the 'tax gap' where various economic interests escape the blind spot of the law.

The biggest issue in the technical aspect of taxation is how to resolve the ‘lock-in effect’. Because the current system taxes assets only when they are sold, taxpayers tend to hold on to assets for long periods of time to avoid or delay paying taxes. This freezing effect is criticized for hindering the original function of the market, which requires capital to flow to profitable and efficient destinations, and ultimately resulting in a distortion of capital allocation. Therefore, the core logic of this proposal is to correct this distortion by taxing unrealized profits and to enable taxpayers to make investment decisions based on the market logic of economic profitability and efficiency rather than the artificial incentive of tax savings.

Of course, there are realistic questions about whether taxation on unrealized profits is immediately feasible. In particular, for taxpayers who do not have the cash to pay taxes even though the prices of their assets have risen, a contradictory situation may arise where they are forced to sell their assets to pay taxes. To make up for this, various compromises were presented at the discussion meeting. Recognizing unrealized profits as income, but delaying actual tax payment until the time of sale or collecting interest by adding interest according to the deferral period, are discussed as a powerful alternative. In addition, for real estate or unlisted stocks where the market price is unclear, the existing taxation at the time of realization is being maintained, or a method of gradually introducing it limited to high-net-worth individuals and certain financial assets is being carefully considered.

The strengthening of taxation on asset income does not stop at simply taxing unrealized profits, but is leading to calls for comprehensive tax reform, including the revival of financial investment income tax and an increase in the effective tax rate for the ultra-high income class. The criticism that the relatively lenient tax structure on capital income compared to labor income is deepening income inequality is also a long-standing problem in Korean society. However, there are also many concerns that this radical tax reform could lead to a sharp contraction in the asset market. In particular, we should not lightly overlook the economic community's warning that if unrealized profit taxation is introduced in an unstable stock market, it may accelerate investor withdrawal and hinder companies' ability to raise funds.