Introduction
Methodology and data
Database and sample selection
Criterion | Remaining households (N) |
---|---|
Households with ≥ 1 car who replaced ≥ 1 car in 2009 | 225,431 |
Households where any car data were missing or where cars run on unconventional fuels were excluded | 135,226 |
Households with unemployed household members excluded | 115,962 |
Households who moved or changed workplace excluded | 29,737 |
Outliers excluded | 28,876 |
Main sample | 28,876 |
Sample representativity
Model specification
Variable | Unit | Before | After | ||
---|---|---|---|---|---|
Mean | S.D. | Mean | S.D. | ||
Driving distance | Kilometres/year | 1904 | 1062 | 1945 | 1094 |
Fuel efficiency | km/l petrol-eq. | 11.3 | 1.6 | 11.7 | 1.7 |
No. of cars | – | 1.32 | 0.55 | 1.42 | 0.63 |
Car weight | Kilogrammes | 1399 | 198 | 1457 | 200 |
Car power | Kilowatts | 94.7 | 26.1 | 100.8 | 27.5 |
Adjusting type-approved values to real-world fuel consumption
Results
Bivariate analysis
Δ Driving distance | Δ Fuel efficiency | Driving distance baseline | Δ Income | Δ No. of cars | Δ Car weight | Δ Car power | |
---|---|---|---|---|---|---|---|
Δ Driving distance | 1 | ||||||
Δ Fuel efficiency | − .001 | 1 | |||||
Driving distance baseline | − .411*** | .026*** | 1 | ||||
Δ Income | .088*** | − .011 | .066*** | 1 | |||
Δ No. of cars | .539*** | .010 | − .130*** | .083*** | 1 | ||
Δ Car weight | .066*** | − .587*** | − .073*** | .009 | − .077*** | 1 | |
Δ Car power | .031*** | − .624*** | − .057*** | .017** | − .047*** | .665*** | 1 |
Multivariate analysis
Main sample | Single-car households | Extended sample* | ||||
---|---|---|---|---|---|---|
Variable | Estimate | p value | Estimate | p value | Estimate | p value |
(Intercept) | 466.04 | 0.000 | 542.48 | 0.000 | 559.19 | 0.000 |
Δ Fuel efficiency (α) | 39.46 | 0.000 | 31.32 | 0.000 | 56.41 | 0.000 |
Driving distance baseline (β1) | − 0.31 | 0.000 | − 0.42 | 0.000 | − 0.32 | 0.000 |
Δ Income (β2) | 0.05 | 0.000 | 0.03 | 0.000 | 0.03 | 0.000 |
Δ No. of cars (β3) | 891.32 | 0.000 | n.a. | n.a. | 964.75 | 0.000 |
Δ Car weight (β4) | 0.63 | 0.000 | 0.51 | 0.000 | 0.71 | 0.000 |
Δ Car power (β5) | − 0.07 | 0.783 | − 0.06 | 0.793 | 0.29 | 0.044 |
Rebound effect | 0.24 | 0.25 | 0.30 | |||
R2 | 0.42 | 0.25 | 0.48 | |||
N | 28,876 | 17,053 | 112,442 |
Comparison of socio-demographic groups
Variables | Efficiency coefficient (α) | Rebound effect | p value | 95 % C.I. lower | 95 % C.I. upper | p-diff | n |
---|---|---|---|---|---|---|---|
Green labelled car Other car | 2.3 55.0 | 0.02 0.32 | 0.673 0.000 | − 0.05 0.28 | 0.08 0.36 | 0.00 0.00 | 5059 23,817 |
Increased fuel efficiency Reduced fuel efficiency | 23.0 56.4 | 0.13 0.34 | 0.000 0.000 | 0.08 0.26 | 0.19 0.42 | 0.00 0.00 | 16,139 12,382 |
Urban Rural | 39.8 37.9 | 0.25 0.18 | 0.000 0.000 | 0.21 0.12 | 0.29 0.26 | 0.10 0.10 | 22,600 6276 |
Multi-person household Single-person household | 45.0 29.8 | 0.24 0.23 | 0.000 0.000 | 0.19 0.16 | 0.28 0.29 | 0.81 0.81 | 17,754 11,122 |
Single-car household Multi-car household | 64.7 32.5 | 0.27 0.25 | 0.000 0.000 | 0.21 0.21 | 0.34 0.29 | 0.62 0.62 | 10,307 18,569 |
Income quartile 1 Income quartile 2 Income quartile 3 Income quartile 4 | 32.8 34.5 44.4 40.6 | 0.22 0.22 0.26 0.21 | 0.000 0.000 0.000 0.000 | 0.14 0.15 0.18 0.15 | 0.30 0.29 0.33 0.28 | 0.72 0.58 0.54 0.68 | 7219 7219 7219 7219 |