My dissertation consists of three empirical studies on technical inefficiency, productivity change, price efficiency, and collusive pricing. In the first essay, I measure technical and allocative efficiency of Vietnam's fisheries processing firms, which are a key factor underlying the impressive achievements of the fisheries sector over the last two decades. I estimate a shadow cost system using a Bayesian Markov Chain Monte Carlo procedure. I find that firms have not fully exploited economies of scale. They are likely to over-utilize labor relative to capital. Small firms tend to have higher allocative efficiency than larger ones. Interestingly, based on this measure, while in other regions state-owned enterprises do worse than private enterprises, the pattern seems to be reversed in the Mekong delta. In addition, large fluctuations in efficiency change and productivity change across several firms may indicate the vulnerability of weaker firms to competition from international trade.In the second essay, I estimate a multiple-input, multiple-output directional distance function for 78 electric utilities spanning from 1988 to 2005. During this period, the U.S. electric power industry underwent remarkable changes in environmental regulations and a wave of restructuring. I find that restructuring in electricity markets tends to improve technical efficiency of deregulated utilities. Deregulated utilities that have NOx control equipment below average are likely to invest less on these devices, but utilities with above average NOx control equipment do the opposite. The reverse applies to particulate removal devices. However, the whole sample spends more on these two as well as SO2 control systems and reduce their electricity sales slightly. In addition, increased capital investments in SO2 and NOx control equipment do not reduce SO2 and NOx emissions, respectively. But expansions of particulate control systems cut down SO2 emissions greatly. Moreover, the utilities have been shifted increasingly farther from the frontier over time. Inward shifting of the production frontier, as well as declining technical efficiency and productivity growth, probably results from the implementation of stricter environmental regulations.In the last essay, I investigate the extent of collusive pricing in the U.S. tobacco industry. In November 1998, the four largest tobacco companies and the attorneys general of more than 40 states reached the Master Settlement Agreement under which the companies would pay $206 billion to the states for recovery of their smoking-related health care costs. However, the allocation of annual payments among the tobacco companies based on their relative market shares and stringent marketing restrictions raised concern over the possibility that the industry would become more collusive. Using the nonparametric tests developed by Ashenfelter and Sullivan (1987), I find strong evidence supporting this argument. Specifically, when the real tax rates increased, the tobacco companies raised their prices after 1998 much more frequently than before the adoption of the settlement. Strikingly, even when the nominal tax rates remained constant, they pushed up prices faster than the consumer price index for majority of the time.