ECON 140 (ECONOMETRICS) EXAM 2025 WITH 100%
ACCURATE SOLUTIONS
OLS formula – Answer✅️
☑️Yi = B0 + B1(Xi) +
gamma(Ci) + Ei
** what’s gamma and Ci ???
OLS assumptions – Answer✅️ ☑️-without the
treatment, the treatment and control group
would have had the same outcome
OLS assumtion: formula – Answer✅️
☑️Cov(Xi, Ei)
=0
E[Yi(0)|Ti=1] = E[Yi(0)|Ti=0]
Yi(0) {outcome of treatment group in absense of
treatment} would have been the same for Ti=1
and Ti=0 groups
, OLS dangers – Answer✅️
☑️-OVB
-[/Systematic (?)] Measurement Error
-Reverse Causality
_Misspecification of Functional Form
-Sample Selection
*anything causing error to be correlated with X
OVB – Answer✅️
☑️
Reverse Causality – Answer✅️
☑️
Misspecification of Functional Form – Answer✅️
☑️
Sample Selection – Answer✅️
☑️
OLS Estimation: - Answer✅️ ☑️ATT (Average effect
of the Treatment on the Treated)
Randomized Control Trial – with perfect
compliance – Answer✅️ ☑️use OLS formula:
Yi = B0 + B1X1 + Ei
ACCURATE SOLUTIONS
OLS formula – Answer✅️
☑️Yi = B0 + B1(Xi) +
gamma(Ci) + Ei
** what’s gamma and Ci ???
OLS assumptions – Answer✅️ ☑️-without the
treatment, the treatment and control group
would have had the same outcome
OLS assumtion: formula – Answer✅️
☑️Cov(Xi, Ei)
=0
E[Yi(0)|Ti=1] = E[Yi(0)|Ti=0]
Yi(0) {outcome of treatment group in absense of
treatment} would have been the same for Ti=1
and Ti=0 groups
, OLS dangers – Answer✅️
☑️-OVB
-[/Systematic (?)] Measurement Error
-Reverse Causality
_Misspecification of Functional Form
-Sample Selection
*anything causing error to be correlated with X
OVB – Answer✅️
☑️
Reverse Causality – Answer✅️
☑️
Misspecification of Functional Form – Answer✅️
☑️
Sample Selection – Answer✅️
☑️
OLS Estimation: - Answer✅️ ☑️ATT (Average effect
of the Treatment on the Treated)
Randomized Control Trial – with perfect
compliance – Answer✅️ ☑️use OLS formula:
Yi = B0 + B1X1 + Ei
