This study estimates the determinants of the exit behavior in a concentrating industry that encounters industrial restructuring. The swine industry has experienced the dramatic change in many perspectives, especially farm size and operation numbers, in the United States in past decades and the process still continues. Characterized by industrialized hog production, hog industry provides available data and a significant case study for exploring the issue related to structural change and exit behaviors. This study uses U.S. swine industry data to explore the factors that affect small producers' quitting decision. Unbalanced panel data for 14 major hog production states from 1988-2003 was collected. Fixed effects models and random effects models, one-factor or two-factor are all considered in this study. By observing the aggregate leaving pattern: exit rates, we can evaluate how exogenous shocks, macroeconomic conditions, technological improvement and scale of production, drive small-farm operators' decision-making. Moreover, this study evaluates two driving forces of leaving behavior, voluntarily or non-voluntarily. It is implied that timing of leaving is important. In addition, this paper evaluates the existence of a crowding-out effect among large-scale modernized entrants and small traditional family producers' exit.Comparing the models by R-square, F-test and Hausman test, this study chooses one-factor random-effects model as the major results and two-factor fixed-effects model as auxiliary results.Whether the exiting behaviors of producers, especially for smaller producers, are volunteering or forcing to leave, that is related to the fairness of competition within the industry. In this study we find out new large-scale entrants do not displace the incumbents. It means that the crowding-out force does not happen between large-scale producers and small-scale producers. Alternatively, we find out that the expanding larger producers' hog operation sizes pressure the small producers to leave swine industry. As for this expanding is benign or hurtful, this study does not provide the evidences to judge. As for technology improvement, it affects the survival space for smallest hog producers. It implies that smallest category of producers have difficulty to access the improvement technology. Furthermore, technology improvement plays a buffer role for producers with scale of 100-499 head of hogs. It implies that for producers in this category need to change its efficient capacity, match the necessity of improved technology and/or raise the management skills to survive in this business. Illustrate the exiting behaviors might increase the forecasting precision of supply for the whole industry, especially established the relationship between exit behaviors and supply, that might help clarifying further hog cycles. In this study we conclude that hog price is the factor to affect the incentives of raising-hogs of producers with scale of 100-499 head. In addition, from this study, we do not observe that state-specific factors affect the exit behaviors of small producers strongly enough. It implies that state-level public programs or policies, such as environmental regulation, do not have crucial influence on small producers' exodus.