(1) The basis for making a decision must be clear, that is, whether to put the remaining money in the bank to earn interest or invest in real estate, depending on which one earns more.

(2) Make important assumptions, such as deposit interest rate and loan interest rate are related to deposit time. To simplify the problem, you can consider the total income of 5 years, 10 or 30 years, and set the deposit as a fixed term. And family income is also related to time. You can assume that it is the same as the GDP growth rate, and the GDP growth rate is constant at 8%. Housing depreciation rate, property tax and other similar treatment.

(3) The most important thing is to establish the relationship between real estate investment income and family income, rental income, deposit and loan interest rates, housing depreciation rate, housing vacancy rate and property tax (you can also only consider the factors that you think are more important and ignore a few minor factors, because it is too complicated to consider all, sometimes it is unnecessary), and determine the independent variable, which can be family income (other factors are mainly controlled by objective conditions and relatively fixed). It can be expected that if the family income is high, investing in real estate is basically more profitable. How to invest in real estate if the family income is low?

(4) It is very important to have your own ideas, plus a good analysis and improvement of the model, which is very important, usually to determine the standards of papers at different levels. It is also important to check the information. We should have a full understanding of each of the above terms, so as to make reasonable and appropriate assumptions and solve the problem more simply and reasonably.