How do you interpret the estimated value of coefficient of EDU in the following equation:

ln(SALARY)= 1 + 0.02ln(EDU)

where SALARY is annual salary (in thousands) and EDU is years of education?

a.
we predict that 1 year increase in years of education leads to $2000 increase in salary

b.
we predict that 1% increase in years of education leads to 2% increase in salary

c.
we predict that 1 year increase in years of education leads to 2% increase in salary

d.
we predict that 1% increase in years of education leads to 0.02% increase in salary

Respuesta :

Answer:

The correct option is d

Step-by-step explanation:

From the question we are told that

The equation is [tex]ln (SALARY) = 1 + 0.02 ln(EDU)[/tex]

generally

[tex]ln (e) = 1[/tex]

=> [tex]ln (SALARY) = ln (e) + 0.02 ln(EDU)[/tex]

Apply log rules

=> [tex]ln (SALARY) = ln[ e(EDU)^{0.02} ][/tex]

=> [tex]SALARY = e(EDU)^{0.02}[/tex]

When EDU is increase by 1% we have that

[tex]\frac{1}{100} * EDU + EDU[/tex]

=> [tex]1.01 EDU[/tex]

So the new SALARY will now be

[tex]SALARY'' = e(1.01EDU)^{0.02}[/tex]

The ratio by which the new SALARY will increase is obtain by dividing the value of new SALARY (SALARY'' ) with that of the former SALARY (SALARY) and this mathematically represented as

[tex] \frac{SALARY'' }{SALARY} = \frac{e*1.01 (EDU)^{0.02}}{e (EDU)^{0.02}}[/tex]

=> [tex]\frac{SALARY ''}{SALARY} = 1.0002[/tex]

Generally the percentage increase of salary is mathematically evaluated as

[tex]k= (\frac{SALARY''}{SALARY} - 1 ) * 100[/tex]

=> [tex]k= (1.0002 - 1 ) * 100[/tex]

=> [tex]k= 0.02 \%[/tex]