Table 1.
The “final” model of log migrants as a function of year, log population of origin, log area of origin, log population of destination, log distance, and indicator variables; specification of the model in R and resulting coefficients and statistics
| Call: lm (formula = logmigrants ∼ I (year−1985) + logppnorig + logareaorig + logppndest + logdistance + orig.indicator + dest.indicator + orig.is.datasource + dest.is.datasource) | |||
|---|---|---|---|
| Coefficients | Estimate | SE | t value |
| (Intercept) | −2.5135 | 0.0886 | −28.3730 |
| I (year–1985) | 0.0016 | 0.0003 | 5.1670 |
| Logppnorig | 0.8631 | 0.0083 | 103.6400 |
| Logareaorig | −0.2103 | 0.0066 | −31.9050 |
| Logppndest | 0.3604 | 0.0089 | 40.7010 |
| Logdistance | −0.9685 | 0.0102 | −94.5470 |
| orig.indicatorAustralia | 1.1295 | 0.0436 | 25.8900 |
| orig.indicatorBelgium | −0.2557 | 0.0404 | −6.3300 |
| orig.indicatorDenmark | −0.0441 | 0.0409 | −1.0760 |
| orig.indicatorGermany | 0.0699 | 0.0409 | 1.7080 |
| orig.indicatorItaly | 0.1844 | 0.0401 | 4.5960 |
| orig.indicatorNetherlands | 0.0250 | 0.0408 | 0.6120 |
| orig.indicatorSweden | 0.1602 | 0.0473 | 3.3840 |
| orig.indicatorUnited Kingdom | 0.2486 | 0.0397 | 6.2580 |
| dest.indicatorAustralia | 1.4362 | 0.0558 | 25.7360 |
| dest.indicatorBelgium | 0.1314 | 0.0524 | 2.5090 |
| dest.indicatorCanada | 0.8557 | 0.0457 | 18.7160 |
| dest.indicatorDenmark | 0.2560 | 0.0523 | 4.8980 |
| dest.indicatorGermany | 0.5875 | 0.0502 | 11.7020 |
| dest.indicatorItaly | 0.7551 | 0.0493 | 15.3090 |
| dest.indicatorNetherlands | 0.4805 | 0.0509 | 9.4480 |
| dest.indicatorSpain | 0.6400 | 0.0470 | 13.6210 |
| dest.indicatorSweden | 0.2528 | 0.0696 | 3.6340 |
| dest.indicatorUnited Kingdom | 0.6284 | 0.0491 | 12.7910 |
| dest.indicatorUnited States of America | 1.1444 | 0.0457 | 25.0180 |
| orig.is.datasourceAustralia | −0.3038 | 0.0633 | −4.8010 |
| orig.is.datasourceBelgium | 0.4595 | 0.0626 | 7.3410 |
| orig.is.datasourceDenmark | 0.2340 | 0.0642 | 3.6450 |
| orig.is.datasourceGermany | 0.4872 | 0.0613 | 7.9500 |
| orig.is.datasourceItaly | −0.4761 | 0.0630 | −7.5620 |
| orig.is.datasourceNetherlands | 0.2112 | 0.0645 | 3.2750 |
| orig.is.datasourceSweden | −0.0733 | 0.0658 | −1.1140 |
| orig.is.datasourceUnited Kingdom | 1.3529 | 0.0682 | 19.8440 |
| dest.is.datasourceAustralia | −0.0317 | 0.0719 | −0.4420 |
| dest.is.datasourceBelgium | 0.5479 | 0.0716 | 7.6510 |
| dest.is.datasourceCanada | 0.1462 | 0.0638 | 2.2930 |
| dest.is.datasourceDenmark | 0.2687 | 0.0721 | 3.7270 |
| dest.is.datasourceGermany | 0.5646 | 0.0674 | 8.3730 |
| dest.is.datasourceItaly | −0.2356 | 0.0687 | −3.4280 |
| dest.is.datasourceNetherlands | 0.4550 | 0.0718 | 6.3360 |
| dest.is.datasourceSpain | −0.2294 | 0.0678 | −3.3850 |
| dest.is.datasourceSweden | 0.1258 | 0.0831 | 1.5140 |
| dest.is.datasourceUnited Kingdom | 1.4979 | 0.0762 | 19.6680 |
| dest.is.datasource United States of America | NA | NA | NA |
| Residual standard error: 0.6957 on 43610 degrees of freedom | |||
| Multiple R2: 0.5693, Adjusted R2: 0.5689 | |||
| F statistic: 1,372 on 42 and 43,610 DF, nominal P value: < 2.2e-16 | |||
Because the assumption of independence among observations was implausible, conventional measures of statistical significance were probably inapplicable. The destination.is.data.source parameter for the U.S. is labeled “NA” because one of the destination.is.data.source variables must be eliminated to prevent a singularity in estimating the coefficients. See SI Text for details.