We have found that due to the result of model testing, our seniors have removed “direction” variable- which Gretl has listed as insignificant.. We built multiple regression model with so
Trang 1FOREIGN TRADE UNIVERSITY
ECONOMETRICS ASSIGNMENT
What affects people’s choices of purchasing apartment?
Trang 2
Table of Contents
Introduction 3
Methodolody 4
Econometrics Model I Model 4
II Variables meaning 1 Specific explanations of variables .4
2 Data descriptions 5
III Results 1 Running Model 7
2 Testing Model 7
a Testing Normality 7
b Testing Multicollinearity 8
c Testing Heteroskedasticity 9
d Testing Autocorrelation 11
e Testing Specification Bias 11
IV Conclusions 1 Final Regression Model 12
2 Explanation 12
V Sugesstions 13
Appendix 14
INTRODUCTION
Housing nowadays seems to be a never-ending problem of society due to the rapid growth of population while lands are limited It leads to an obvious result that the
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Trang 3prices of real estate, especially in big cities like Ho Chi Minh City or Hanoi, go up and down unstably The fluctuation of real estate price confuses customers, who are largely newly married couples seeking for their own nests
Since the scarcity of usable areas are still questioning land planners, a lot of
sensitive investors start investing in apartments, which seems to be the best
solution to housing problems at the moment Apartment brings a lot of advantages
to both contractors and customers: modest area required, cheaper cost, more people contracting at the same time, better security……
To figure out what affects the price of an apartment, we have done a research on which factors the price is dependent to bring a clearer view and support to
everyone who is planning to buy an apartment The question given is: “Which
elements affecting Hanoi’s apartment price?”
A METHODOLOGY
So far we have collected date from some reliable internet sources like
www.nhadatvideo.com, www.nhadat24h.net as well as consulted some
assignments of senior students to clarify what we should implement and develop and continue researching We have found that due to the result of model testing, our seniors have removed “direction” variable- which Gretl has listed as
insignificant Though in reality, most Hanoi people when deciding to buy a house
or an apartment usually care whether its direction is suitable to the owner’s lunar age
Trang 4We collected about 120 reliable observations and then chose the most sufficient once again Our group ended up with 86 observations We built multiple
regression model with some assumed variables which we suppose may have direct effect on Hanoi apartment’s price per square, constructing process, floor or
square… Our group has tested 5 assumptions of the model that are normality, multicollinearity, heteroscedascity, autocorrelation and specification bias
B ECONOMICTRICS MODEL
Prps = ß1 + ß2 *area + ß3*pro + ß4*flr + ß5*sqr + ß6*dir + ui
1 Specific explanation of variables
- Prps: price per square (million VND/ m2)
- Area: whether that apartment is close to city center or convenient or not ( if
yes = 1, if no =1)
- Pro : constructing process – whether the building is completed or not ( if
yes = 1, if no = 0)
- Flr : floor – where the apartment is located
- Sqr : square (in m2)
- Dir : direction ( if the direction is south, south east or south west => =1; if
the direction is north, north east , north west, west =>0)1
Expectation in signs
- ß1 : it depends
- ß2 : positive ( apartments near city center tend to be more expensive than
those in suburb )
- ß3 : positive ( people prefer building that has been finished so that they can
directly judge if the apartment they are going to buy is beautiful or not)
- ß4 : it depends ( some people like low floor so that it would be more
convenient for them to go around, some like higher floor in order to avoid noise and city pollution)
- ß5 : negative ( the larger the apartment is, the less expensive per square)
- ß6 : positive ( if the apartment faces good direction, its price will be raised
higher)
2 Data description
1 This direction is only based on the weather, not referring to owner’s lunar age
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Trang 5a Price per square
Summary statistics, using the observations 1950/01/02 - 1951/08/20
for the variable 'prps' (86 valid observations)
Summary Statistics, using the observations 1950/01/02 - 1951/08/20
for the variable prps (86 valid observations)
b Area
Summary Statistics, using the observations 1950/01/02 - 1951/08/20
for the variable area (86 valid observations)
c Process
- Completed: 61/86
- Uncompleted: 25/86
d Floor
Summary Statistics, using the observations 1950/01/02 - 1951/08/20
for the variable floor (86 valid observations)
e Square
Summary Statistics, using the observations 1950/01/02 - 1951/08/20
for the variable sqr (86 valid observations)
f Direction
- Good direction: 48/86
- Bad direction: 38/86
Trang 7III RESULTS:
1 Running Model:
Using Gretl, we have the result as above As it shown from the result, we have some initial conclusions:
- R- squared is 0.600373 meaning that approximately 60% of the variables
can be explained by the model
- There are five independent variables which can explain the dependent
variable
- All of these five independent variables are statistically significant.
The initial Regression Model can be defined as:
Prps = 31.2517 + 7.67236*area + 5.04203*Pro – 0.285302*Flr – 0.107574*Sqr
+ 3.80662*Dir + ui
2 Testing Model:
a Testing normality:
From the model, we test normality by using command Tests Normality of residuals in Gretl The result is:
Trang 8The p-value from the result is 0.0718 > 0.05 The residuals are normally distributed.
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Trang 9b Testing Multicollinearity:
There are two ways to test Multicollinearity by using Gretl
First of which is using the VIF ( variance inflating factor) :
From the result, we can see that VIF < 10 Model is free from Multicollinearity
Or we can use the Correlation Matrix:
The correlation between the variables is smaller than 0.8 Multicollinearity does
not exist in the model
Trang 10c Testing Heteroskedasticity:
Using White test in Gretl, we can see if the Model is suffered from Heteroskedasticity
or not The result is:
As can be inferred from the result, the p-value is 0.203444 > 0.05 The Model does not suffer from heteroskedasticity.
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Trang 11d Testing autocorrelation:
The p- value in this result is 0.951 > 0.05 There is no autocorrelation in this
model
e Testing Specification bias:
Using Ramsey’s RESET test, we will have the result as below:
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The p-value is 0.143 which is greater than 0.05 Model is adequately specificated
IV CONCLUSION:
1 Final Regression Model:
Prps = 31.2517 + 7.67236*area + 5.04203*Pro – 0.285302*Flr – 0.107574*Sqr +
3.80662*Dir
2 Explanation:
- R- squared is 0.600373 meaning that approximately 60% of the variables can
be explained by the model
- Remarks on variables:
Variable name Conjecture of
Trend of impact
True Trend of impact Explanation
taken into consideration, the dependent variable reaches the estimated
value of 31.2517.
city center will be 7.67236
million VND more expensive than that in the suburb
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Trang 13Process (Pro) Positive Positive People have a tendency to
prefer completed apartment
to unfinished ones A m2 of
a finished one will be
5.04203 million VND more
expensive than that of unfinished one
Floor (Flr) It depends Negative Lower floor seems to beat
higher floor in terms of safety in people’s thinking For one extra floor will cost
you 0.285302 million VND
less
Square (Sqr) Negative Negative One extra m2 will safe you
0.107574 million VND.
Direction (Dir) Positive Positive In reality, for Asian people,
direction will always sit on top of other problems when
it comes to purchasing estate And a m2 of an apartment facing good
direction will take 3.80662
millionVND more out of your wallet in comparison with that which faces bad direction
V SUGGESTIONS:
To buy a good apartment, customer should have a close enough check on 3
main elements : contractor's reputation, products' quality and contract in order for you to make a right purchase
Firstly, contractor's reputation plays a very important role in your decision
making It is better if you have a basic understanding about his/her ability or financial statement to avoid being tricked or waiting continuously without
knowing when you can get your apartment
Secondly, product's quality is also very essential Since real estate is a kind of special products, it involves with many external factors: legal base, certificate, neighboring areas, surrounding environment The more you have knowledge
Trang 14of your about-to-buy apartment, the more advantages you have when
negotiating about pricing
Last but not least, contract matters are always one of the most concerns to customers You should carefully check all the terms before signing Process delayed is the most popular risk when you buy an apartment which has not been finished, so in this situation, fine is the best way to urge the contractor to
complete the contract on time Also, you should check the bias between the apartment's are in reality with that in contract to avoid future complaints
APPENDIX
Customers and the taste of apartments, together with the price
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