Explaining the Decision to Plagiarize: An Empirical Test of the Interplay Between Rationality, Norms, and Opportunity

¹Transactional costs are incurred as instructors try to protect themselves against the violation of trust by their students and students try to protect themselves against the suspicion of their instructors. Educational institutions need to spend time and financial resources to stop the occurrence of plagiarism. The teaching and learning atmosphere at universities is injured by the instructors’ constant suspicion (Weinstein and Dobkin Citation2002). Moreover, when they later seek employment, students who ultimately received their university degree on the basis of plagiarized papers appear on paper to possess greater skills and efficiency than they actually do in reality.

²The unconscious appropriation of ideas and sentences, so-called cryptomnesia (Taylor 1965), will not be addressed in this article.

³As a consequence, this theoretical approach is applicable to a variety of decisions, which could be considered a strength of this theory.

⁴The assumption of rationality does not imply that muggers (or economic professors) calculate costs and benefits of available alternatives to seventeen decimal places—merely that they tend to choose the one that best achieves their objectives” (Friedman Citation1995:43). For criticism see De Mesquita and Cohen (Citation1995).

⁵Becker and Mehlkop (Citation2006; cf. Nagin and Paternoster, Citation1993) found support for Becker's theory in their empirical study on shoplifting and tax evasion. Eide (2000) provides empirical evidence (which is however not coherent) for the model in a variety of different surveys (e.g., Piliavin et al. Citation1986). Kroneberg and colleagues (Citation2010) list several studies that approve RCT empirically, but also many that show mixed results.

⁶Even the other RCT camp can interpret norms as part of a person's moral system, which precedes the actual decision-making process (Becker and Mehlkop Citation2006; Lindenberg Citation1983; Opp Citation2012).

⁷As far as we know, there is as yet no empirical test of the interaction between norms and opportunities. Since our empirical testing is derived directly from theoretical propositions and because there were no propositions available for this interaction, we refrained from including this term in our models. In an explorative fashion, we tested whether there is a considerable statistical relation between opportunity and norms, but no model even exhibited a significant interaction between them. In order to apply parsimonious modelling, we did not include this insignificant interaction term. For the sake of saving space, we did not report on the models here. Nor is there a compelling theoretical argument for including a three-way interaction between utility, norms, and opportunity. For explorative reasons, however, we did test such a three-way interaction. It does not become significant in our models and its results are also left unreported due to space limitations.

⁸Also due to spatial limitation, we focus on empirical findings that could fit to the theoretical propositions of the model presented above. Plagiarism has been a research topic in several scientific disciplines (e.g., in Psychology). Empirical research in this area focuses on procrastination or motivation (Jordan Citation2001; Rettinger et al. Citation2004; Roig and DeTommaso Citation1995).

⁹Possibly, the probability does not cross a threshold necessary to unfold effects. Perhaps students do not get enough information about the whole subject of plagiarism.

¹⁰Participants could choose cash incentives, vouchers for an on-line store or donations for two well-known charity organizations—UNICEF and Amnesty International (5 Euro for each option).

¹¹Only participants who completed the questionnaire in t ₁ got an invitation to t ₂ .

¹²Results are available on request.

¹³In many studies researchers ask about plagiarism directly (e.g., Cochran et al. Citation1999). Using the signalling word “plagiarism,” an underestimation of this variable is more likely because of social desirability. We did not use this word and checked, additionally, for a social desirability bias by using the German short scale of the Balanced Inventory of Desirable Responding (BIDR; Winkler et al. Citation2006, cf. Paulhus Citation1991). This scale consists of two subscales: self-deceptive enhancement (SDE) and impression management (IM). There was no significant or substantive positive effect of both scales. The coefficient of the variables did not change. Due to space limitations, results are not reported here.

¹⁴Items: “I know how to engage in this behaviour to my advantage.” and “It is not difficult for me to engage in this behaviour.”

¹⁵Items: “It gives me a bad conscience.”; “It is against my moral beliefs.”; “For me, such behaviour is reprehensible.”

Incidence rate ratios. 95% confidence intervals in brackets. *p < .05; **p < .01; ***p < .001 (two-sided).

¹⁶There are several other problems in addition to these expenditures (e.g., Collins et al. Citation2007; Crisp Citation2004): plagiarism that remains undetected through sampled checking; texts inaccessible to searching software (like off-line sources or on-line journals with access permissions); lack of detection of translations or re-written parts of texts.

¹⁷Universities can register plagiarists on a blacklist and observe their papers with more vigilance.