This thesis is composed of three separate yet related empirical studies. In Chapter 2, we empirically investigate the effects of inflation uncertainty on output growth for the U.S. economy using both monthly and quarterly data over 1960-2009. Employing a Markov regime switching approach, we show that inflation uncertainty obtained from a Markov regime switching GARCH model exerts a negative and regime dependent impact on growth. We show that the negative impact of inflation uncertainty on growth is almost 2 times higher during the low growth regime than that during the high growth regime. We verify the robustness of our findings using quarterly data. In Chapter 3, we empirically examine whether there are asymmetries in the real effects of monetary policy shocks across business cycle and whether financial depth plays an important role in dampening the effects of monetary policy shocks on output growth using quarterly U.S. data over the period 1981:QI--2009:QII. Applying an instrumental variables estimation in Markov regime switching methodology, we document that the impact of monetary policy changes on growth is stronger during recessions. We also find that financial development is very prominent in dampening the real effects of monetary policy shocks especially during the periods of recession. In Chapter 4, we empirically search for the causal link between energy consumption and economic growth employing a Markov switching Granger causality analysis. We carry out our investigation using quarterly U.S. real GDP and total energy consumption data over the period 1975:QI--2009:QIV. We find that there are changes in the causal relation between energy consumption and economic growth. Our results show that energy consumption has predictive content for real economic activity. The causality running from energy consumption to output growth seems to be strongly apparent only during the periods of recession and energy crisis. We also reveal that output growth has predictive power for energy consumption and this power evidently arises during the periods of expansion.

Although the number of subsidy and countervailing duty cases, both at national and WTO level is declining, they still hold centre stage in the trade wars that are the hallmark of modern international economy. Suffice it to mention the “Foreign Sales Corporations” case, the “softwood lumber” cases and the ongoing “US-EC large civil aircraft” dispute. There are several reasons for this. On the one hand, the multilateral regulation of subsidies can strongly impinge on governmental autonomy in the management of the national economy. On the other, the boundaries of subsidisation are often quite uncertain as subsidies can overlap with quite distinct areas in the public management of the economy, such as taxation. Probably as a result of the foregoing factors, the multilateral discipline on subsidies was slow to develop and it is only with the Uruguay Round that a fully fledged, wide-ranging regime took shape, while the identification of countervailable subsidies and the conditions under which they can be countered have been left for long to domestic countervailing duty proceedings. The United States, for a long time the main user of CVD proceedings, developed a much more sophisticated and detailed regime than the GATTs. The competitive margin provided by US administrative practice has enabled it to impose its perspective on the shaping of the multilateral regime, firstly as a result of the Uruguay Round negotiations, and secondly because of the creative interpretation of the WTO rules, especially by the Appellate Body. On the other hand, in implementing the WTO regime the United States has often been able to withstand attempts to change its domestic regime, although some of its aspects are not necessarily consistent with the WTO rules. The success of the United States, however, has been far from complete as the US has not been able to impose its viewpoint on decisive aspects of the subsidy regulation in the GATT and in the WTO system.