This thesis uses innovative approaches to analyse energy policy interventions aimed at enhancing the environmental sustainability of energy use as well as its consequential welfare implications. First, we examine the relationship between energy efficiency improvement and CO2 emissions at the macro level. We use the Index Decomposition Analysis to derive energy efficiency by separating out the impact of shifts in economic activity on energy intensity. We then employ econometric models to relate energy efficiency and CO2 emissions accounting for non-economic factors such as consumers lifestyle and attitudes. The applications for 13 OPEC and 30 OECD countries show that at the country-group and individual country level, increase in energy intensity for OPEC is associated with both deteriorations in energy efficiency and shifts towards energy-intensive activities. The model results suggest that the reduction in energy efficiency in general go in tandem with substantial increases in CO2 emissions. The decline in energy intensity for OECD can be attributed mainly to improvements in energy efficiency which is found to compensate for the impact on CO2 emissions of income changes. The results confirm the empirical relevance of energy efficiency improvements for the mitigation of CO2 emissions. The method developed in this chapter further enables the separate assessment of non-economic behavioural factors which according to the results exert a non-trivial influence on CO2 emissions. Secondly, having empirically confirmed the relationship between energy efficiency improvements and CO2 emission at the macro level in Chapter 2, we investigate potential underlying drivers of energy efficiency improvements taking into account potential asymmetric effects of energy price change in Chapter 3. This is crucial for designing effective and efficient policy measures that can promote energy efficiency. In addition to the Index Decomposition Analysis used to estimate the economy-wide energy efficiency in Chapter 2, we also use Stochastic Frontier Analysis and Data Envelop Analysis as alternative methods. The driving factors are examined using static and dynamic panel model methods that account for both observed and unobserved country heterogeneity. The application for 32 OECD countries shows that none of the three methods leads to correspondence in term of ranking between energy efficiency estimates and energy intensity at the country level corroborating the criticism that energy intensity is a poor proxy for energy efficiency. The panel-data regression results using the results of the three methods show similarities in the impacts of the determinants on the energy efficiency levels. Also, we find insignificant evidence of asymmetric effects of total energy price but there is proof of asymmetry using energy specific prices. Thirdly, in Chapter 4 we offer an improved understanding of the impacts to expect of abolishing fuel price subsidy on fuel consumption, and also of the welfare and distributional impacts at the household level. We develop a two-step approach for this purpose. Key aspect of the first step is a two-stage budgeting model to estimate various fuel types elasticities using micro-data. Relying on these estimates and the information on households expenditure shares for different commodities, the second step estimates the welfare (direct and indirect) and distributional impacts. The application for Nigeria emphasises the relevance of this approach. We find heterogeneous elasticities of fuel demand among household groups. The distributional impact of abolishing the kerosene subsidy shows a regressive welfare loss. Although we find a progressive loss for petrol, the loss gap between the low- and high-income groups is small relative to the loss gap from stopping kerosene subsidy, making the low-income groups to suffer a higher total welfare loss. Finally, from the highlighted results, we draw the following concluding remarks in chapter 5. Energy efficiency appears a key option to mitigate CO2 emissions but there is also a need for additional policies aiming for behavioural change; energy specific prices and allowing for asymmetry in analysing the changes in energy efficiency is more appropriate and informative in formulating reliable energy policies; the hypothesis that only the rich would be worse-off from fuel subsidy removal is rejected and the results further suggest that timing of the fuel subsidy removal would be crucial as a higher international oil price will lead to higher deregulated fuel price and consequently, larger welfare loss.

Consumption-based environmental impact trends for the Swedish economy have been generated and analysed in order to determine their levels compared to official production-based data, and to determine whether or not the Swedish economy has decoupled growth in domestic final demand from worldwide environmental impact. Three energy resources (oil, coal and gas use, as well as their aggregate fossil fuel use) and seven emissions (CO2, CH4, N2O, SO2, NOx, CO and NMVOC, as well as the aggregate CO2 equivalents) were studied. An augmented single-regional input–output model has been deployed, with world average energy and emission intensities used for products produced abroad. A new method for updating input–output tables for years missing official input–output tables, was also developed. For each of the resources and the emissions, two time series were generated based on two different revisions of Swedish national accounts data, one for the period 1993–2003, the other for the period 2000–2005. The analysis uses a recently revised time series of environmental data from the Swedish environmental accounts, as well as recently published global environmental data from the IEA and from the EDGAR emissions database (all data from 2010 or later). An index decomposition analysis was also performed to detect the various components of the time series. For fossil fuels consumption-based data don't differ much from production-based data in total. For the greenhouse gases there is a clear increase (CO2eq emissions increase approximately 20 % from 1993–2005, mainly driven by an increase in CH4 emissions), resulting from increased emissions abroad due to the increased demand for imported products. This suggests Sweden has not decoupled economic growth from increasing greenhouse gas emissions – contrary to what the slightly decreasing official production-based UNFCCC data say. For the precursor gases (SO2, NOx, CO and NMVOC), emissions are generally decreasing, with the exception of SO2 and NOx which increase in the second time series. For all emissions studied, consumption-based data lie at much higher levels than the official production-based UNFCCC data. However, further research is needed regarding the resolution of the data of the energy use and the emissions generated abroad by the Swedish domestic final demand. Also, extension of the time series and of the environmental parameters to such things as material use is needed to find out with more certainty to what extent Swedish growth has been sustainable or not. / I den här studien har konsumtionsbaserade tidsserier på svensk fossilbränsleanvändning och på svenska utsläpp av luftföroreningar tagits fram i avsikt att jämföra dessa med de officiella produktionsbaserade tidsserierna. Syftet har varit att avgöra om det svenska samhällets påverkan på resurser och miljö ur ett konsumtionsperspektiv har minskat eller ökat över tiden, och framförallt om en frikoppling har skett mellan den svenska ekonomiska tillväxten och den påverkan Sverige har på miljön i Sverige och utomlands. Tre fossila bränslen (olja, kol, gas samt aggregatet fossila bränslen) och sju luftföroreningar (CO2, CH4, N2O, SO2, NOx, CO och NMVOC samt aggregatet CO2-ekvivalenter) har analyserats. En enkelregional input–output-modell har tagits fram, utökad med globala medelintensiteter för den produktion som sker utanför Sverige. En ny metod har också utvecklats för att generera input–output-tabeller för år där officiella sådana tabeller saknas. För samtliga energiresurser och luftföroreningar, upprättades två stycken tidsserier, baserat på två olika revisioner av ekonomiska data från nationalräkenskaperna. Den första tidsserien täcker åren 1993–2003, och den andra åren 2000–2005. Miljödata togs från nyligen reviderade tidsserier från de svenska miljöräkenskaperna samt från IEA och den internationella luftföroreningsdatabasen EDGAR (alla data reviderade 2010 eller senare). En komponentanalys utfördes också, för att identifiera olika bidragande komponenter i tidsserierna. Vad gäller fossila bränslen i sin helhet, uppstår ingen markant skillnad mellan konsumtionsbaserade och produktionsbaserade data. Vad gäller växthusgaserna kan en klar ökning urskiljas (20 procents ökning av CO2-ekvivalenter mellan 1993–2005; CH4-utsläppen har där bidragit mest), vilket beror på stigande utsläpp utomlands orsakade av ökad efterfrågan på importerade produkter. Detta antyder att den svenska tillväxten ännu inte frikopplats från ökade utsläpp av växthusgaser, vilket står i motsats till den minskning i utsläpp som de officiella produktionsbaserade siffrorna från UNFCCC-rapporteringen redovisar. För övriga luftföroreningar (SO2, NOx, CO och NMVOC), sker i allmänhet en minskning, förutom för SO2 och NOx som ökar i den andra tidsserien. Samtliga luftföroreningar ligger vidare på en betydligt högre nivå jämfört med UNFCCC-rapporteringen. Mer detaljerade studier behövs dock på den energiförbrukning och de utsläpp som svensk slutlig användning för med sig utomlands. Tidsserierna behöver också förlängas och fler miljövariabler som t.ex. materialanvändningen behöver studeras för att kunna dra säkrare slutsatser kring i vilken utsträckning som den svenska tillväxten har varit hållbar eller ej.