econometrics homework

1.
a) reg sleep totwrk
b) SLEEP = 3586.38 - 0.15*TOTWRK
c) The estimate of B1, which is the average that people sleep who do not work in a week, is 3586.38 minutes . However, each minute that a person works per week, reduces sleeping in 0.15 minutes per week.
2.
a)
- average salary = 865.86
- average tenure = 7.95
b) 5 CEOs are in the first year as CEO
c) shown in stata
d) ln(SALARY) = 6.51 + 0.0097*CEOTEN
e) Every additional year of a person as a CEO position improves the salary 0.97%.
3.
a)

b) reg sprice livarea
c) SPRICE = -30069.2 + 9171.711*LIVAREA
d) The estimate of B1 is -30069.2. Does not have interpretation because the selling price of a home cannot be a negative value.
e)

f) reg sprice livarea2
g) SPRICE = 57728.31 + 212.611*LIVAREA2
h) dsprice/dlivarea = 2*212.611LIVAREA = 425.22LIVAREA
i) If livarea= 1500 square feet, then dprice/dlivarea= 425.22*15= $6378.3
If livarea= 1600 square feet, the dprice/dlivarea= 425.22*16= $6803.52
The marginal effect of an additional 100 square feet of living area for a home is $425.22.
j)

The quadratic model fits better
k) gen lnprice=ln(price) reg lnsprice livarea
l) ln(SPRICE) = 10.697 + 0.056*LIVAREA
m) Every additional square meter in the living area increases the selling price by about 5.6%
4.
a)

b) reg sprice age
c) SPRICE = 137403.6 - 627.161*AGE
d) The estimate of B1 which is the average selling price of a new house, is 137403.6. However, each additional year that a home has decreases the price in $627.161
e)

f) gen lnsprice=ln(sprice) reg lnsprice age
g) ln(SPRICE) = 11.74597 - 0.00476*AGE
h) Every additional year that a home has, decreases the selling price 0.476%
5.
a)
- average salary= 957.95
- average IQ= 101.28
- standard deviation IQ= 15.05
b) WAGE = 116.9916 + 8.30*IQ
An increase in IQ of 15 raise the monthly salary by 8.03*15= $124.5
c) ln(WAGE)= 5.89 + 0.0088*IQ
If IQ increases by 15 points= 0.0088*15= 13.2% 6.
a) ln (RD) = a +