The problems of single financing channel, narrow coverage and insufficient fund scale of social security fund have become the main obstacles to the improvement of China's social security system. In order to ensure the normal operation of the social security system, we must broaden the financing channels, make up for the funding gap and adopt diversified capital operation methods.

(1) Diversified raising of social security funds and establishment of a sound social security system.

1. Take financial measures to make up for the hidden debts formed by historical debts.

First of all, adjust the structure of fiscal expenditure, increase the proportion of social security expenditure in the whole budget expenditure, and make up for the fund gap. Secondly, financing through the realization of state-owned assets. As part of the current state-owned assets itself comes from the accumulation of pensions, it is inherently reasonable and feasible to allocate a certain share of state-owned assets to social security funds. Finally, issue long-term bonds for financing. By expanding the scale of national debt, we can absorb and digest the historical debt of endowment insurance, thus making the implicit government debt explicit, which not only embodies intergenerational equity, but also will not cause welfare losses to a certain generation because of the change of endowment insurance fund raising mode.

2. Increase the sources of social security funds through tax channels.

In the long run, collecting social security tax in time is the best way to raise funds. Social security tax has stability and legitimacy and is an ideal source of social security funds. The government can also change the social security tax rate according to the needs of economic development and play its regulatory role in stabilizing economic operation. In the case that social security tax has not been levied, other taxes, especially those with income distribution function, can be temporarily used as supplementary sources of social security funds. At present, by strengthening the collection of personal income tax, some personal income tax can be accepted as social security income. Inheritance tax and capital gains tax can also be sources of social security funds. In addition, on the basis of the existing consumption tax, special consumption tax on social security can be levied on some very high-end consumer goods.

3. Expand social security coverage and increase fund-raising income.

Improve relevant laws and regulations, expand the scope of social insurance premium collection to all kinds of enterprises in cities and towns, and all insured units should pay pension, unemployment and medical insurance premiums in full and on time according to regulations. You can choose to cover migrant workers in cities. Since the reform and opening up, migrant workers in cities have become the basic force to improve the level of urbanization in China. However, due to various reasons, they are not included in the urban social security system, and other factors lead to migrant workers still in a state of mobility, which seriously hinders the further improvement of China's urbanization level.

(two) to strengthen the endowment insurance fund raising and operation supervision.

With the gradual development of market economy, legislation has become the key to the smooth implementation of the old-age insurance system, and the security items, security levels, financing methods and management services must be regulated by law. Therefore, China should formulate relevant laws on old-age insurance as soon as possible, and clarify the obligations and responsibilities of economic entities to undertake old-age insurance funds in the form of legislation, so that old-age insurance can be followed by laws.

In addition to establishing a sound legal system, we should also establish strong social supervision. In order to ensure the steady growth of income, the data submitted by the insured enterprises should be audited by the labor and tax departments, and with the help of the advantages of the tax departments, combined with the management of enterprise income tax before tax and personal income tax, the payment base should be approved according to law to increase the payment amount. In addition, with the development of economy and the change of price, the daily adjustment mechanism of pension fund expenditure should be standardized, and an internationally accepted pension adjustment system should be established according to inflation index.

(3) Actively explore new investment channels to make social security funds an important mechanism for macro-control.

1. holds shares in state-owned enterprises and participates in the ownership reform and corporate governance reform of state-owned enterprises.

Social security funds holding state-owned enterprises can achieve three main effects. First, due to the public ownership of social security funds, there will be no loss of state-owned assets. Second, the original planning system has caused the pensions of retired employees and soon-to-be-retired employees of state-owned enterprises to be converted into state-owned assets, and some state-owned assets are allocated to social security fund legal persons, which is actually the part of wealth nominally belonging to the state. Return to the beneficiaries of the social security fund. Third, the social security fund has established a structural system of fund legal person, manager, trustee and investor, and the government and the public have formed a supervision organization. It is conducive to ensuring the preservation and appreciation of state-owned assets and the reform of the management system of state-owned enterprises.

2. Participate in housing financing and play the role of inter-temporal allocation of funds.

In the process of housing system reform in China, large-scale housing loans are needed as support. At present, it is difficult to fundamentally solve the financing problem of housing reform by taking provident fund loans as the mainstay and commercial loans as the supplement. Because the term of deposits absorbed by commercial banks is no longer than five years, if commercial banks increase housing loans in large quantities, the liquidity of assets will be greatly reduced and the time structure of assets and liabilities will be unreasonable. Therefore, it is necessary to open up new financing channels for housing purchase funds, so as not to seriously restrict housing financing and increase the future operating risks of banks.

We can learn from the experience of Singapore's central provident fund system and let pension funds participate in the housing finance industry, because the long-term nature of pension funds can completely solve the problem of "short use of funds" caused by commercial banks' participation in housing finance. Another way is to implement mortgage securitization, so that long-term social security funds such as pension funds can invest in mortgage securities. The implementation of mortgage-backed securitization can transform unsold bank assets into securities that can be traded in the market, which not only increases the liquidity of bank funds, but also solves the contradiction between short-term sources of bank funds and long-term operation of assets.

3. Participate in entity investment, promote industrial upgrading and play a macro-control role.

Participating in infrastructure construction can provide long-term and stable income for social security funds. From the reality of our country, we can consider investing in highway transportation and energy construction, which can support the national economic construction on the one hand and obtain relatively stable returns from the completed projects on the other. In addition to infrastructure, the investment direction of social security funds can also choose high-tech industries, bioengineering industries, environmental protection industries and other key areas with long-term significance and high industrial relevance to China's economic development, so as to accelerate the upgrading, rationalization and environmental protection of the national economic structure.

4. Investing in overseas capital markets

China's securities market has just started, and its investment behavior is very irregular, lacking a stable rate of return. In this case, investing some social security funds overseas can not only make the investment portfolio more diversified, but also reduce the correlation between investments, which will not only help social security funds avoid and disperse the systemic risks faced by domestic investment, but also improve the return on assets and promote the preservation and appreciation of funds.