Do climate variations explain bilateral migration? A gravity model analysis

Table 4 Explorations of potential channels between migration and climate change

Dependent variable: log migration flow	(1)	(2)	(3)	(4)
Independent variables:
weighted temperature origin	0.033**	0.008	0.020*	0.018
	(0.016)	(0.016)	(0.012)	(0.013)
weighted precipitation origin	0.004	0.006*	0.006**	0.005*
	(0.004)	(0.003)	(0.003)	(0.003)
state fragility index			0.006	0.006
			(0.006)	(0.006)
Lag.state fragility index			0.010*	0.010*
			(0.006)	(0.006)
*wtemp origin state fragility index**				−0.009
				(0.013)
*wpre origin state fragility index**				−0.004
				(0.003)
*wtemp origin Lag.state fragility index**				−0.004
				(0.014)
*wpre origin Lag.state fragility index**				0.001
				(0.002)
R-squared	0.026	0.018	0.023	0.022
N	5584	8458	13434	13434
RMSE	0.527	0.577	0.557	0.557
F-test	10.22	8.41	16.37	14.15

Note: ***, **, * denote significance levels at one, five and ten percent, respectively. Robust standard errors are reported in parentheses. Controls and year dummies are included. Column (1) uses only countries of origin which exhibit an average share of agricultural land in their total land mass above 50%. Column (2) uses only countries of origin which exhibit an average share of agricultural land in their total land mass below or equal to 50%. Column (3) estimates the model in first differences, adding the state fragility index and its first lag. Column (4) estimates the model in first differences, adding the state fragility index, its first lag, and interactions of the two with the climate variables.