Introduction
Materials and methods
Data
Migration flows and socioeconomic variables
Descriptive statistics | Migration flows (all) | Migration flows (urban) | Migration flows (non-urban) | Logarithm of population | Unemployed population ratio | At most finished primary education population ratio | White population ratio | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sample size (n) | 5100 | 5100 | 5100 | 102 | 102 | 102 | 102 | |||||||
Sum | 3,799,167.00 | 2,916,957.00 | 726,992.00 | 1361.17 | 37.31 | 48.76 | 9.18 | |||||||
Mean | 744.93 | 571.95 | 142.55 | 13.34 | 0.37 | 0.48 | 0.09 | |||||||
Standard deviation | 2276.63 | 2029.07 | 405.54 | 0.84 | 0.12 | 0.13 | 0.07 | |||||||
Minimum | 0.00 | 0.00 | 0.00 | 10.86 | 0.10 | 0.20 | 0.00 | |||||||
Lower quartile | 37.00 | 20.00 | 0.00 | 12.91 | 0.30 | 0.39 | 0.03 | |||||||
Median | 131.00 | 79.00 | 25.00 | 13.45 | 0.36 | 0.49 | 0.08 | |||||||
Upper quartile | 492.25 | 325.25 | 94.00 | 13.83 | 0.43 | 0.57 | 0.14 | |||||||
Maximum | 53,902.00 | 48,572.00 | 10,492.00 | 15.17 | 0.70 | 0.78 | 0.28 | |||||||
Interquartile range | 455.25 | 305.25 | 94.00 | 0.92 | 0.14 | 0.19 | 0.11 | |||||||
Descriptive statistics | Positive maximum temperature anomaly | Negative precipitation anomaly | Soil moisture percentile | Positive SPI | Negative SPI | Logarithm of prior migrant network (all) | Logarithm of prior migrant network (urban) | Logarithm of prior migrant network (non-urban) | ||||||
Sample size (n) | 102 | 102 | 102 | 102 | 102 | 2550 | 2550 | 2550 | ||||||
Sum | 14.60 | −14.40 | 5164.40 | 35.94 | −8.69 | 11,542.18 | 10,327.67 | 7224.68 | ||||||
Mean | 0.14 | −0.14 | 50.63 | 0.35 | −0.09 | 4.53 | 4.05 | 2.83 | ||||||
Standard deviation | 0.24 | 0.21 | 8.15 | 0.38 | 0.18 | 2.84 | 2.88 | 2.68 | ||||||
Minimum | 0.00 | −0.66 | 33.84 | 0.00 | −0.98 | 0.00 | 0.00 | 0.00 | ||||||
Lower quartile | 0.00 | −0.28 | 44.57 | 0.00 | −0.07 | 2.56 | 0.00 | 0.00 | ||||||
Median | 0.00 | 0.00 | 50.43 | 0.24 | 0.00 | 4.87 | 4.47 | 3.09 | ||||||
Upper quartile | 0.26 | 0.00 | 56.09 | 0.68 | 0.00 | 6.57 | 6.16 | 4.91 | ||||||
Maximum | 1.08 | 0.00 | 65.79 | 1.25 | 0.00 | 11.55 | 11.55 | 10.65 | ||||||
Interquartile range | 0.26 | 0.28 | 11.52 | 0.68 | 0.07 | 4.01 | 6.16 | 4.91 |
Climate variables
Methods
Migration flow data as a network
The network model
Results
Climate effects
Model 1 | Model 2 | Model 3 | |||||||
---|---|---|---|---|---|---|---|---|---|
All | Urban | Non-urban | All | Urban | Non-urban | All | Urban | Non-urban | |
(O) population | 0.83** | 0.92** | 1.26** | 0.85** | 0.94** | 1.24** | 0.75** | 0.82** | 1.2** |
(O) unemployed | −0.94** | −1.48** | −0.22 | −1.25** | −1.83** | −0.66 | −1.57** | −2.32** | −0.68 |
(O) primary | −1.23 | −1.56† | 1.89 | −1.58* | −1.84† | 1.44 | −2.53** | −3.19** | 1.1 |
(O) White | 1.06 | 0.66 | 4.59† | 0.36 | 0.23 | 3.71 | −1.44 | −2.23 | 3.08 |
(O) pos Tmax anom | 0.29** | 0.18 | 0.69** | ||||||
(O) neg Precip anom | −0.44** | −0.56** | −0.46† | ||||||
(O) soil moisture | −0.03** | −0.03** | −0.03* | ||||||
(O) pos SPI | 0.13† | 0.19* | −0.04 | ||||||
(O) neg SPI | −0.13 | −0.33† | 0.21 | ||||||
(D) population | 0.76** | 0.81** | 0.04 | 0.77** | 0.78** | 0.08 | 0.75** | 0.84** | 0.25 |
(D) unemployed | −1.07** | −1.64** | −1.39* | −0.54† | −1.23** | −0.73 | −0.43 | −0.92* | −0.23 |
(D) primary | −2.58** | −3.72** | −2.96† | −2.21** | −3.52** | −1.48 | −2.14** | −2.78** | 0.43 |
(D) White | 5.83** | 8.39** | −0.3 | 6.61** | 8.79** | 3.69 | 6.89** | 10.17** | 6.63* |
(D) pos Tmax anom | 0.08 | 0.19† | −0.85** | ||||||
(D) neg Precip anom | 0.63** | 0.64** | 0.47† | ||||||
(D) soil moisture | −0.01 | 0 | −0.01 | ||||||
(D) pos SPI | −0.15* | −0.28** | −0.2 | ||||||
(D) neg SPI | 0.01 | 0.04 | 0.79* | ||||||
(Dyad) distance | −1.45** | −1.4** | −1.67** | −1.47** | −1.43** | −1.72** | −1.45** | −1.4** | −1.64** |
(Dyad) contiguity | 0.65** | 0.62** | 0.97** | 0.64** | 0.61** | 0.95** | 0.65** | 0.62** | 0.99** |
R2(log) | 0.8337 | 0.8249 | 0.7023 | 0.8321 | 0.8236 | 0.6999 | 0.8326 | 0.8248 | 0.6996 |
DIC | 1.89e+10 | 5.7e+10 | 8.53e+09 | 2.17e+10 | 6.01e+10 | 8.73e+09 | 2.24e+10 | 6.32e+10 | 7.66e+09 |
Model comparison
All | Urban | Non-urban | |||||||
---|---|---|---|---|---|---|---|---|---|
AMEN | MESF | Gravity | AMEN | MESF | Gravity | AMEN | MESF | Gravity | |
(O) population | 0.83** | 0.59** | 0.62** | 0.92** | 0.63** | 0.69** | 1.26** | 0.04 | 0.14 |
(O) unemployed | −0.94** | −0.06 | 0.03 | −1.48** | −0.17 | −0.04 | −0.22 | −0.11 | −0.1 |
(O) primary | −1.23 | 2.8** | 2.41** | −1.56† | 2.66** | 2.22* | 1.89 | 1.37 | 1.79 |
(O) White | 1.06 | 3.03** | 3.5* | 0.66 | 4.41** | 5.15** | 4.59† | −2.36 | −1.99 |
(O) pos Tmax anom | 0.29** | 0.47** | 0.48** | 0.18 | 0.5** | 0.52** | 0.69** | 0.41** | 0.42** |
(O) neg Precip anom | −0.44** | −0.42** | −0.35** | −0.56** | −0.33** | −0.26* | −0.46† | −0.64** | −0.56** |
(D) population | 0.76** | 0.45** | 0.39 | 0.81** | 0.5** | 0.44† | 0.04 | − 0.22 | − 0.19 |
(D) unemployed | −1.07** | −0.91** | −0.93* | −1.64** | −1.81** | −1.85** | −1.39* | −0.63* | −0.61 |
(D) primary | −2.58** | −2.49** | −2.49* | −3.72** | −3.95** | −4.03** | −2.96† | −0.62 | −0.69 |
(D) White | 5.83** | 3.03** | 2.88 | 8.39** | 4.66** | 4.45** | − 0.3 | 3.82* | 3.73 |
(D) pos Tmax anom | 0.08 | 0.08 | 0.06 | 0.19† | 0.11* | 0.1 | −0.85** | −0.52** | −0.57** |
(D) neg Precip anom | 0.63** | 0.67** | 0.6** | 0.64** | 0.74** | 0.68** | 0.47† | 0.41** | 0.32† |
(Dyad) distance | −1.45** | −1.04** | −0.94** | −1.4** | −1.1** | −0.95** | −1.67** | −0.85** | −1.18** |
(Dyad) contiguity | 0.65** | 0.36** | 0.54** | 0.62** | 0.32** | 0.48** | 0.97** | 0.57** | 0.62** |
R2(log) | 0.8337 | 0.7254 | 0.5203 | 0.8249 | 0.7073 | 0.5292 | 0.7023 | 0.5147 | 0.271 |
All | Urban | Non-urban | |||||||
---|---|---|---|---|---|---|---|---|---|
AMEN | MESF | Gravity | AMEN | MESF | Gravity | AMEN | MESF | Gravity | |
(O) population | 0.85** | 0.73** | 0.73** | 0.94** | 0.8** | 0.83** | 1.24** | 0.43* | 0.41 |
(O) unemployed | −1.25** | −0.48** | −0.48† | −1.83** | −0.53** | −0.51* | −0.66 | −0.68** | −0.63† |
(O) primary | −1.58* | 2.83** | 2.75** | −1.84† | 3.16** | 3.13** | 1.44 | 0.36 | 0.62 |
(O) White | 0.36 | 1.45 | 1.44 | 0.23 | 2.93** | 3.02† | 3.71 | −2.91† | −2.71 |
(O) soil moisture | −0.03** | −0.13** | −0.13** | −0.03** | −0.15** | −0.15** | −0.03* | −0.1** | −0.08** |
(D) population | 0.77** | 0.22 | 0.22 | 0.78** | 0.22 | 0.24 | 0.08 | −0.31 | −0.33 |
(D) unemployed | −0.54† | −0.97** | −0.99* | −1.23** | −2.22** | −2.24** | −0.73 | −0.17 | −0.21 |
(D) primary | −2.21** | −1.87** | −1.73† | −3.52** | −3.03** | −2.99 ** | −1.48 | −1.23 | −1.19 |
(D) White | 6.61** | −0.19 | −0.07 | 8.79** | 0.56 | 0.55 | 3.69 | 7.8** | 7.89** |
(D) soil moisture | −0.01 | 0.08** | 0.06* | 0 | 0.03 | 0.02 | −0.01 | 0.18** | 0.16** |
(Dyad) distance | −1.47** | −1.07** | −0.94** | −1.43** | −1.11** | −0.95** | −1.72** | −0.85** | −1.18** |
(Dyad) contiguity | 0.64** | 0.36** | 0.54** | 0.61** | 0.33** | 0.48** | 0.95** | 0.58** | 0.62** |
R2(log) | 0.8321 | 0.7268 | 0.5201 | 0.8236 | 0.7046 | 0.5304 | 0.6999 | 0.5157 | 0.2713 |
All | Urban | Non-urban | |||||||
---|---|---|---|---|---|---|---|---|---|
AMEN | MESF | Gravity | AMEN | MESF | Gravity | AMEN | MESF | Gravity | |
(O) population | 0.75** | 0.35* | 0.43† | 0.82** | 0.38** | 0.46* | 1.2** | 0.13 | 0.26 |
(O) unemployed | −1.57** | −0.63** | −0.53* | −2.32** | −0.69** | −0.54* | −0.68 | −0.8** | −0.77* |
(O) primary | −2.53** | −0.22 | −0.38 | −3.19** | −0.08 | −0.29 | 1.1 | −2.26* | −1.82 |
(O) White | −1.44 | −1.52 | −0.89 | −2.23 | −0.22 | 0.65 | 3.08 | −5.9** | −5.58* |
(O) pos SPI | 0.13† | 0.18** | 0.12† | 0.19* | 0.15** | 0.08 | −0.04 | 0.28** | 0.29** |
(O) neg SPI | −0.13 | −0.42** | −0.4* | −0.33† | −0.42** | −0.43** | 0.21 | −0.37* | −0.37 |
(D) population | 0.75** | 0.14 | 0.08 | 0.84** | 0.13 | 0.08 | 0.25 | −0.5* | −0.6 |
(D) unemployed | −0.43 | −0.59* | −0.67 | −0.92* | −1.63** | −1.68** | −0.23 | −0.24 | −0.34 |
(D) primary | −2.14** | −0.81 | −0.8 | −2.78** | −2.19 ** | −2.21* | 0.43 | 0.73 | 0.47 |
(D) White | 6.89** | 0.86 | 1.27 | 10.17** | 1.99† | 2.33 | 6.63* | 6.11** | 6.27* |
(D) pos SPI | −0.15* | −0.38** | −0.33 ** | −0.28** | −0.45** | −0.4** | −0.2 | −0.15* | −0.14 |
(D) neg SPI | 0.01 | −0.07 | −0.09 | 0.04 | 0.02 | 0 | 0.79 * | −0.26 | −0.23 |
(Dyad) distance | −1.45** | −1.05** | −0.94** | −1.4** | −1.09** | −0.95** | −1.64** | −0.85** | −1.18 ** |
(Dyad) contiguity | 0.65** | 0.36** | 0.54** | 0.62** | 0.32** | 0.47** | 0.99** | 0.57** | 0.62** |
R2(log) | 0.8326 | 0.7253 | 0.5197 | 0.8248 | 0.708 | 0.5299 | 0.6996 | 0.5102 | 0.2673 |
Socioeconomic and latent factor effects
Migrant network effects and their interactions with climate variability
Model 1 | Model 2 | Model 3 | Model 4 | Model 5 | |
---|---|---|---|---|---|
(O) population | 0.819** | 0.831** | 0.652** | 0.654** | 0.69** |
(O) unemployed | −1.345 ** | −0.936 ** | −1.434 ** | −0.984** | −0.847** |
(O) primary | −1.875 * | −1.229 | −1.181 | −0.682 | −0.345 |
(O) White | −0.243 | 1.063 | −2.232 | −1.231 | −1.272 |
(O) posTmax | 0.286** | 0.229* | 0.209 | ||
(O) negPrec | −0.438** | −0.499** | −0.885** | ||
(D) population | 0.744** | 0.764** | 0.578** | 0.586** | 0.593** |
(D) unemployed | −0.589 * | −1.068 ** | −0.681* | −1.135** | −1.029** |
(D) primary | −2.375** | −2.581** | −1.63* | −1.89** | −1.619* |
(D) White | 6.405** | 5.83** | 4.108** | 3.425** | 3.499** |
(D) posTmax | 0.078 | 0.009 | −0.256† | ||
(D) negPrec | 0.634** | 0.571** | 0.08 | ||
(Dyad) mij.past | 0.17** | 0.167** | 0.179** | ||
(Dyad) mji.past | 0.115** | 0.114** | 0.132** | ||
(Dyad) posTmax.i × mij.past | −0.052† | ||||
(Dyad) posTmax.i × mji.past | 0.05 | ||||
(Dyad) posTmax.j × mij.past | 0.08* | ||||
(Dyad) posTmax.j × mji.past | −0.029 | ||||
(Dyad) negPrec.i × mij.past | 0.054 | ||||
(Dyad) negPrec.i × mji.past | 0.03 | ||||
(Dyad) negPrec.j × mij.past | 0.029 | ||||
(Dyad) negPrec.j × mji.past | 0.075* | ||||
(Dyad) distance | −1.433** | −1.447** | −0.605** | −0.618** | −0.615** |
(Dyad) contiguity | 0.657** | 0.649** | 0.453** | 0.452** | 0.446** |
R2(log) | 0.8321 | 0.8337 | 0.8331 | 0.8348 | 0.8368 |
DIC | 2.19e+10 | 1.89e+10 | 1.6e+10 | 1.48e+10 | 1.67e+10 |
Model 2 | Model 4 | Model 5 | |||||||
---|---|---|---|---|---|---|---|---|---|
All | Urban | Non-urban | All | Urban | Non-urban | All | Urban | Non-urban | |
(O) population | 0.831** | 0.917** | 1.26** | 0.654** | 0.701** | 1.137** | 0.69** | 0.739** | 1.142** |
(O) unemployed | −0.936 ** | −1.477 ** | −0.22 | −0.984** | −1.558** | −0.154 | −0.847** | −1.539** | 0.095 |
(O) primary | −1.229 | −1.563† | 1.89 | −0.682 | −0.86 | 2.099 | −0.345 | −0.418 | 1.897 |
(O) White | 1.063 | 0.659 | 4.59† | −1.231 | −1.824 | 3.149 | −1.272 | −1.793 | 3.018 |
(O) posTmax | 0.286** | 0.183 | 0.69** | 0.229* | 0.126 | 0.62** | 0.209 | 0.075 | 0.588* |
(O) negPrec | −0.438** | −0.563** | −0.46† | −0.499** | −0.634** | −0.494* | −0.885** | −1.198** | −0.577† |
(D) population | 0.764** | 0.807** | 0.04 | 0.586** | 0.595** | −0.014 | 0.593** | 0.604** | −0.017 |
(D) unemployed | −1.068** | −1.644** | −1.39* | −1.135** | −1.757** | −1.428* | −1.029** | −1.41** | −1.427* |
(D) primary | −2.581** | −3.718** | −2.96† | −1.89** | −2.777** | −2.373 | −1.619* | −2.408** | −1.819 |
(D) White | 5.83** | 8.394** | −0.3 | 3.425** | 5.458** | −1.517 | 3.499** | 5.646** | −0.887 |
(D) posTmax | 0.078 | 0.194† | −0.85** | 0.009 | 0.12 | −0.897** | −0.256† | −0.221 | −1.236** |
(D) negPrec | 0.634** | 0.64** | 0.47† | 0.571** | 0.565** | 0.441† | 0.08 | 0.091 | 0.136 |
(Dyad) mij.past | 0.167** | 0.192** | 0.177** | 0.179** | 0.235** | 0.175** | |||
(Dyad) mji.past | 0.114** | 0.105** | 0.124** | 0.132** | 0.093** | 0.125** | |||
(Dyad) posTmax.i × mij.past | −0.052† | −0.096* | −0.111† | ||||||
(Dyad) posTmax.i × mji.past | 0.05 | 0.098* | 0.129* | ||||||
(Dyad) posTmax.j × mij.past | 0.08* | 0.032 | 0.09 | ||||||
(Dyad) posTmax.j × mji.past | −0.029 | 0.044 | 0.04 | ||||||
(Dyad) negPrec.i × mij.past | 0.054 | 0.156** | −0.143* | ||||||
(Dyad) negPrec.i × mji.past | 0.03 | −0.021 | 0.158* | ||||||
(Dyad) negPrec.j × mij.past | 0.029 | 0.057 | 0.083 | ||||||
(Dyad) negPrec.j × mji.past | 0.075* | 0.06 | −0.007 | ||||||
(Dyad) distance | −1.447** | −1.401** | −1.67** | −0.618** | −0.774** | −0.925** | −0.615** | −0.751** | −0.942** |
(Dyad) contiguity | 0.649** | 0.619** | 0.97** | 0.452** | 0.384** | 0.583** | 0.446** | 0.386** | 0.589** |
R2(log) | 0.8337 | 0.8249 | 0.7023 | 0.8348 | 0.8246 | 0.7015 | 0.8368 | 0.8282 | 0.7025 |
DIC | 1.89e+10 | 5.7e+10 | 8.53e+09 | 1.48e+10 | 4.14e+10 | 4.13e+09 | 1.67e+10 | 3.47e+10 | 6.75e+09 |