This thesis applies several econometric methods to a selection of country panels to study how growth is influenced by financial development and government debt. The first part presents the thesis discussion, including a synthesis on financial development, government debt, money supply, and economic growth. The second part deepens the discussion with three stand-alone essays. The first essay models how financial development affects growth through utilization of technological innovation. Based on explicit modeling of the innovation channel of finance, the results show a significant and positive sign for the interaction term between the measure of a country’s own innovation and financial development in the most important specifications. This suggests that the innovation channel of finance is likely to be positively relevant to growth. The second essay examines effects of venture capital investment on economic growth in a similar framework. The findings demonstrate that the interaction of venture capital with innovation has a positive and statistically significant coefficient. Further, the joint impact related to venture capital and its interactions is positive in most specifications, suggesting that venture capital is probably a relevant factor for growth. The third essay delves deeply in the effects of general government debt and general government external debt on growth of real GDP. It explores the long-standing endogeneity problem, includes other relevant debt concepts besides government total debt, revisits the issue whether there are threshold values for the government debt ratio, examines the effect of debt on GDP components and structure, uses timely and extensive datasets and extensive robustness analysis, and runs meta-regressions of the results of this and a many of other studies. Even with correction for endogeneity, the study finds modest evidence of a negative and significant growth impact for government debt. The evidence is not robust over all samples and specifications. The final essay also reports evidence of a negative and significant effect of government external debt in the sample of developed economies. The findings overall comport with those of recent papers that conclude that there is no universal threshold value for a government debt ratio that would hold across all countries. Further, government debt appears to decrease the private-investment-to-GDP ratio, but increases the GDP ratio for household consumption. The meta-regression analysis shows that the study’s results on how specification features affect the estimate of the government debt coefficient are broadly in line with those of other studies.

We develop a microeconomic model of endogenous growth where clean and dirty technologies compete in production and innovation–in the sense that research can be directed to either clean or dirty technologies. If dirty technologies are more advanced to start with, the potential transition to clean technology can be difficult both because clean research must climb several rungs to catch up with dirty technology and because this gap discourages research effort directed towards clean technologies. Carbon taxes and research subsidies may nonetheless encourage production and innovation in clean technologies, though the transition will typically be slow. We characterize certain general properties of the transition path from dirty to clean technology. We then estimate the model using a combination of regression analysis on the relationship between R&D and patents, and simulated method of moments using microdata on employment, production, R&D, firm growth, entry and exit from the US energy sector. The model’s quantitative implications match a range of moments not targeted in the estimation quite well. We then characterize the optimal policy path implied by the model and our estimates. Optimal policy makes heavy use of research subsidies as well as carbon taxes. We use the model to evaluate the welfare consequences of a range of alternative policies.