Call:
lm(formula = f, data = d)

Residuals:
    Min      1Q  Median      3Q     Max 
-21.810  -5.068  -0.027   6.014  19.567 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept)  -8.6847     7.0829  -1.226   0.2218    
gdp           6.9983     0.5047  13.867   <2e-16 ***
population   -0.7970     0.2995  -2.662   0.0085 ** 
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 7.905 on 175 degrees of freedom
Multiple R-squared:  0.5392,	Adjusted R-squared:  0.5339 
F-statistic: 102.4 on 2 and 175 DF,  p-value: < 2.2e-16