gravity (version 1.1)

hm_summary: Head and Mayer consistent summary statistics

Description

Summary of estimates function that, if is used with default options, provides estimation results are consistent with the Stata methods used in Head2014;textualgravity. This function is adapted from the work of Isidore Beautrelet.

Usage

hm_summary(model, robust = FALSE, ...)

Value

Summary lm object.

Arguments

model

(Type: lm) Regression object obtained by using the estimation methods from this package or a generic method such as lm or glm. Some particular classes (gpml, nbpml, negbin and nls) don't return R squared and F statistic.

robust

(Type: logical) Determines whether a robust variance-covariance matrix should be used. By default is set to FALSE.

If set TRUE the estimation results are consistent with the Stata code provided at the website Gravity Equations: Workhorse, Toolkit, and Cookbook when choosing robust estimation.

...

additional arguments to be passed to tobit.

Examples

# Example for CRAN checks:
# Executable in < 5 sec
library(dplyr)
data("gravity_no_zeros")

# Choose 5 countries for testing
countries_chosen <- c("AUS", "CHN", "GBR", "BRA", "CAN")
grav_small <- filter(gravity_no_zeros, iso_o %in% countries_chosen)

# Using OLS for testing
fit <- ols(
  dependent_variable = "flow",
  distance = "distw",
  additional_regressors = c("rta", "contig", "comcur"),
  income_origin = "gdp_o",
  income_destination = "gdp_d",
  code_origin = "iso_o",
  code_destination = "iso_d",
  uie = FALSE,
  robust = FALSE,
  data = grav_small
)

fit2 <- hm_summary(fit, robust = FALSE)