This dissertation consists of four different essays which examine the pricing decisions, costs and strategic considerations of natural gas suppliers in the European and North American natural gas markets. The first essay investigates how Gazprom, Russia’s natural gas exporter, responds to diversification efforts in Europe. I employ a theoretical Nash bargaining model and estimate a correlated random effects model to find that Gazprom charges lower prices to importers who are less dependent on Russian supplies of natural gas than those who are more dependent. The second paper specifically explores Gazprom’s pricing of natural gas in the Baltic States and determines that Gazprom charges lower than monopoly prices to its Baltic clients, despite the fact that the Baltic Region was completely dependent on Russian supplied natural gas until very recently. I propose two possible explanations for Gazprom's apparent deviation from its profit-maximizing behavior. First, I provide evidence that Gazprom priced its natural gas to avoid fuel substitution from natural gas to fuel oil. Second, I find that the Baltic States possess some countervailing bargaining power in price negotiations with Gazprom. The third paper studies peak load underground storage decisions in salt caverns in the Gulf Region of the United States. I estimate the cost of injecting natural gas into an underground salt cavern storage facility over varying storage levels to understand how injection costs respond to increased demand for storage. The estimated cost function should aid in underground storage valuation techniques, which tend to assume constant injection costs. The last essay examines the ability of vertically integrated firms, which own assets in both the natural gas and electricity markets, to manipulate natural gas and electricity prices. I develop a theoretical model that examines the incentives of vertically integrated firms to supply and allocate natural gas to the retail and wholesale markets. I show that these firms may choose to favor supply to the retail market in order to increase their profits, especially profits in the electricity sector, and to avoid penalties from failing to adequately supply the retail natural gas market. I further find that anti-competitive behavior is easier to detect when there are no pipeline constraints.