INTRODUCTION A traditional assumption of turnover studies is that turnover is an important organizational problem, and therefore, it should be reduced (Staw, 1980, p. 254). According to the human capital theory (G. Becker, 1962; Schultz, 1961), specific knowledge may impose particular costs on the employer if employees with specific knowledge quit. In the public sector, human resources and their expertise have also been emphasized for producing better organizational performance (Ingraham & Selden, 2002). A government that does not have the right people and expertise at the right time is likely to produce ineffective organizational performance (Government Performance Project Final Assessment, 2003, p. 9). (1) Based on the traditional assumption about turnover effects, most turnover studies have focused on why employees quit and how to prevent employee turnover, regardless of the sectors (e.g., Fields, Dingman, Roman, & Blum, 2005; Herrbach, Mignonac, & Gatignon, 2004; William H. Mobley, 1982; Price, 1977; Tourangeau, Cummings, Cranley, Ferron, & Harvey, 2010; Wagner, 2007). In fact, turnover had not been a big concern in the public sector until the brain drain issue was raised in federal agencies when baby boomers began to retire. Since then, most of the turnover studies have focused on identifying reasons regarding why employees quit, to prevent further resignation in the public sector (e.g., Lewis, 1991; McCabe, Feiock, Clingermayer, & Stream, 2008; Whitaker & DeHoog, 1991; Wilson, 1994). In the private sector, however, researchers have investigated the actual consequences of turnover (e.g., Alexander, Bloom, & Nuchols, 1994; Dalton, Krackhardt, & Porter, 1981; Johnston & Futrell, 1989; J. Shaw, Gupta, & Delery, 2005), based on the question that traditional assumption of turnover effects may be wrong (Abelson & Baysinger, 1984; Staw, 1980). No turnover-effect research on public sector was carried out until Meier and Hicklin (2008), and possible reasons for this neglect of turnover effects include difficulty in both measuring performance (H. Hatry, and Fisk, D., 1992; H. Hatry & Fisk, 1980) and agreeing upon performance measures in the public sector (Meier & Hicklin, 2008, p. 574), and lack of available data as a result. While employee turnover has been an issue in the U.S. in the past decade, not much is known about the turnover effects. Instead of taking the traditional assumption about turnover effects and trying to reduce turnover rates as much as possible, it is necessary for managers to understand how organizational performance will be affected by employee turnover before taking managerial actions to deal with turnover issues. If we just try to maintain turnover at a minimum level, it may cost too much to organizations due to high retention costs that include higher pay and better benefits, like high turnover rates would cost too much to organizations due to high replacement costs that include recruiting and training costs (e.g., Abelson & Baysinger, 1984; Glebbeek & Bax, 2004). The present study probes turnover effects on organizational performance in the public sector and tests the traditional assumption of turnover effects in law enforcement contexts. More specifically, this study focuses on the effects of turnover among sworn officers in municipal police departments after differentiating voluntary and involuntary turnover based on a suggestion of the turnover literature. According to the turnover studies (e.g., Abelson & Baysinger, 1984; McElroy, Morrow, & Rude, 2001; William H. Mobley, 1982; Price, 1977; J. D. Shaw, Delery, Jenkins, & Gupta, 1998), voluntary turnover needs to be differentiated from involuntary turnover before being examined, because treating these two kinds of turnover equally would result in overlooking their different etiologies and consequently mislead. TURNOVER EFFECTS The human capital theory can be a theoretical foundation for a traditional assumption about turnover effects, and for examining the relationship between turnover and organizational performance (J. …