Gravity: a popular tool
Gravity: a recap
Standard proxies for trade costs
Initial equation estimated
Theoretical foundation: historical evolution
Technical derivation
Multilateral resistance: the intuition
Theoretically founded equation
Gravity specification of Multilateral trade resistance
Country fixed effects
Cross country equation (1 year) It is impossible to estimate the coefficient of GDP or other country specific variable
More than 1 year: panel data
Panel data: time-varying fixed effects
Estimating using country-pair fixed effects Random effects: use Hausman test in order to choose between random and fixed effects estimation
Recent theoretical developments
Data sources