New York City real estate appraisal

**Objective**: to find out the fairness and rationality of four different appraisal methods by studying the real estate appraisal data.

**Abstract:** with the booming development of real estate transactions and financial markets, real estate appraisal, as one of the important fields in asset appraisal, is of great significance to asset appraisal. Based on the data analysis, it can be found that from 2004 to 2017, the gap between the municipal equilibrium rate and the unified equilibrium ratio specified by the municipal government is narrowing. In this case data, the largest group per square population density is less than or equal to 100; The least difference of equilibrium rate is the method of using proportion of sales to evaluate, followed by the computer-aided method. If the housing dispersion coefficient is large, the preference is to use the sales proportion for evaluation. If the housing dispersion coefficient is basically stable, the preference is to use the method of employee evaluation sample. Among the types of housing price differences, the largest proportion is appraised by the proportion of sales. The ratio of residential property is the largest in the selection and utilization review, but the ratio of residential property is declining year by year.

**Keywords:** real estate; Assessment methods; fairness

## Case background

With the high speed development of China’s real estate industry and the increasingly mature, the real estate industry has become the new growth point of national economy, but at the same time is also the most prone to real estate bubble economy, the financial risk of industry, therefore, served as a link between bank financial risk and the real estate market of real estate mortgage appraisal system that is extremely important.

The case analysis is the main data of the state of New York in 2004-2017 by using four different evaluation methods to evaluate the real estate industry data, including the year, the municipality directly under the central government’s name, the name of the county, the population density per square, such as data, through the study of the real estate assessment data, it is fair to find out the different evaluation methods.

## Case study

This paper will focus on the fairness of appraisal using different real estate appraisal methods. However, as the real estate market is constantly changing, its price has a strong timeliness. It will be a little troublesome to operate with EXCEL. Using Datafocus products, a large amount of data can be processed quickly and the accuracy of analysis is also high.

## Case analysis

### (I) comprehensive analysis

#### 1. Change of equilibrium rate

First of all, we observe the changes between the municipal equilibrium rate and the uniform equilibrium ratio of the municipal government using different property rights assessment methods in the past 13 years.

图1 均衡率逐年的变化情况

From the figure, it can be observed that from 2004 to 2017, the gap between the municipal equilibrium rate and the unified equilibrium ratio stipulated by the municipal government using different property rights assessment methods is shrinking, and the two have nearly overlapped in 2017.

#### The population density

The population density per square meter obtained from the survey was grouped and the situation of each group was observed.

图2 每平方人口密度分组情况

It can be clearly seen from the word cloud map that in this case data, the maximum population density per square of population density is less than or equal to 100.

#### County equilibrium rate difference

The data of the last three tax years were screened and the scatter plot analysis was carried out for each county with non-zero equilibrium rate.

图3 不同征税年份各县的均衡率差异

It can be seen from the above figure that the equilibrium rate difference in 2015 is still in the situation of large fluctuations, but the equilibrium rate difference in 2017 has been basically stable and fluctuates around 0. It can be seen that the equilibrium rate obtained from the assessment is approaching the uniform equilibrium ratio of the municipality.

### Differences in assessment methods

#### 1. Equilibrium rate difference

It can be seen from the above analysis that the municipal equilibrium rate is being optimized by using different property right assessment methods. Next, we compare different methods of property assessment and find out the best method of property assessment.

CAMA stands for the use of computer assisted quality assessment, Sales Ratio stands for the use of proportion of real estate Sales for assessment, and Review of Reassessment stands for Review and assessment. Sales/Appraisals represent employee Appraisals.

图4 不同评估方法所得均衡率的差异

It can be observed from the figure that the method of evaluating with sales proportion has the smallest equilibrium rate difference, followed by the computer-aided method, and the one with the worst evaluation effect is the review evaluation. In general, the equilibrium rate obtained by using the audit evaluation is larger than the prescribed proportion, while the method of using the employee evaluation sample is generally smaller than the prescribed proportion of the equilibrium rate.

#### 2. Housing dispersion coefficient

Next, we compare the dispersion coefficient of different property right assessment methods.

图5 不同评估方法所得住宅分散系数

It can be observed from the figure that the preference of a large housing dispersion coefficient is to use the sales proportion for evaluation; the preference of a relatively stable housing dispersion coefficient is to use the method of employee evaluation sample; the preference of a slightly decreasing housing dispersion coefficient is to use computer aided quality evaluation.

#### 3. Differences in housing prices

Next, it mainly compares the difference of housing price between different property right assessment methods.

图6 不同评估方法所得住宅价格的差异

It can be observed from the figure that among the types of housing price differences, the largest proportion is estimated by the sales proportion.

#### 4. Residential property ratio

Next, the ratio of residential property of different property assessment methods is compared.

图7 不同评估方法所得住宅物业比率

It can be observed from the figure that the largest proportion of residential property is the selection and utilization review, but the proportion of residential property is decreasing year by year. The second is to use the proportion of sales to evaluate residential property ratio is gradually rising.

### Data pinboard

Finally, these 7 results were imported into the data pinboard of “New York City real estate appraisal”. In order to make the data pinboard more beautiful, the third preset sample was selected in the global style and the “free layout” was selected. Operation results are as follows:

图8 数据看板

## Conclusion

To sum up, from 2004 to 2017, the gap between the municipal equilibrium rate and the unified equilibrium ratio specified by the municipal government is narrowing. In this case data, the largest group per square population density is less than or equal to 100.

In 2015, the equilibrium rate difference is still in the situation of large fluctuations, but in 2017, the equilibrium rate difference has been basically stable and fluctuates around 0. It can be seen that the equilibrium rate obtained from the assessment is approaching the uniform equilibrium ratio of the municipality.

The least difference of equilibrium rate is the method of using proportion of sales to evaluate, followed by the computer-aided method. If the housing dispersion coefficient is large, the preference is to use the sales proportion for evaluation. If the housing dispersion coefficient is basically stable, the preference is to use the method of employee evaluation sample. Among the types of housing price differences, the largest proportion is appraised by the proportion of sales. The ratio of residential property is the largest in the selection and utilization review, but the ratio of residential property is declining year by year.

## Suggestions

1. The sales proportion can be appropriately increased for evaluation;

2. Constantly optimize the appraisal method of real estate and strive for a better appraisal method.