This thesis makes use of a unique and vast dataset of investment and production in the oil and gas industry from 1950 to 2016, to explore the Lucas Paradox and the drivers of returns to capital in the industry. Firstly, the thesis examines to what extent poor countries possess higher average returns to capital than rich countries. Secondly, it investigates whether the differences in returns between countries are correlated with institutional factors, variance and/or asymmetry in the returns. The results demonstrate that poorer countries have enjoyed significantly higher returns to capital than richer countries. Moreover, the findings show that institutional factors such as property rights protection, level of corruption and level of schooling possess a positive and statistically significant correlation with returns to capital. However, both these findings are not particularly economically significant. Variance and asymmetry of the returns appear to be an irrelevant explanation for the Lucas Paradox. On the other hand, asset-specific factors, that were, ex-ante, expected to be merely insignificant control variables, such as the size of the reservoir, or whether the asset is located onshore or offshore, have large R-squared impact on returns to capital. The findings in this thesis are important because the largely insignificant magnitude of country-specific variables highlight the importance of adapting economic development theory to account for sector-specific differences, as emphasized by Feyrer and Caselli (2008). Moreover, the results indicate that profit maximizing oil and gas companies considering new investments in a country should not be overly concerned with the GDP per capita nor the institutional quality of the country in question. Several potential explanations and paths for future studies are delineated.