Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author. co 0 OF T A J. PRED CTI G BLOOD DO ATIO BEH �IOU A thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Marketing at Massey University Palmerston North -iudith Louise Holdershaw 2005 ABSTRACT Understanding and predicting human behaviour has been of particular interest to marketers for many years. The predominant approach to predicting behaviour has relied on attitude-based models; in particular, Ajzen's ( 1 985) theory of planned behaviour is considered the most sophisticated methodology available to researchers for behavioural prediction. However, despite much study and refmement, the predictive abi lity of such models remains relatively poor. Rather than continuing to rely on cognitive models, it is time to consider alternative approaches to predicting behaviour. Labaw ( 1 980) offers one such alternative approach based on information about respondents' environment, knowledge and past behaviour. However, unlike Ajzen's theory of planned behaviour, Labaw's approach to predicting behaviour has not been widely operationalised or tested. Therefore, it is not known whether her approach, using questions that, at least theoretically, have verifiable answers, has greater predictive ability than Ajzen's theory of planned behaviour, based on attitudinal questions. This study compared the predictive ability of Ajzen's attitudinal-based theory of planned behaviour with Labaw's behavioural approach, in the context of blood donation behaviour. In absolute terms, the predictive ability of the two approaches was equivalent; however, Labaw's approach was superior to the theory of planned behaviour from a survey research perspective. Thus, Labaw's approach presents a feasible alternative to attitudinal-based approaches to predicting behaviour. This study also found that behavioural intention to donate blood was a poor predictor of actual (self-reported) donation behaviour. This fmding is important given the widely­ accepted assumption that the best prediction of behaviour is provided by measures of behavioural intention. In addition, the study suggests that researchers need to carefully consider the time interval selected to test the predictive ability of a model i f the results are to have any practical relevance. Variables that help explain the decision to donate blood were also identified. These findings offer blood collection agencies guidance with formulating specific strategies to address blood donor shortages. However, accurately predicting who is most likely to donate blood remains problematic, and further research is needed to extend the results reported in this study. 11 ACKNOWLEDGEMENTS First, 1 'd like to offer special thanks to my supervisor, Professor Phil Gendall , for his endless patience and good-humoured approach to the task of PhD supervision. In particular, I wish to thank Phil for his insightful comments, helpful advice and research guidance, from which I learned much and benefited enormously throughout the entire process. My thanks also extend to my co-supervisor, Associate Professor Malcolm Wright. Like Phil , Malcolm provided helpful advice, unwavering support and good-humoured encouragement. I especially appreciated Malcolm's unfaltering enthusiasm and trademark ability to view every finding as a fascinating and brilliant contribution to marketing! I also wish to thank Dr Alasdair Noble and Zoe Wood for the helpful advice and assistance they provided with the statistical analysis of the data. I am also grateful for the funding provided by Massey University, first, for the Doctoral Scholarship, which provided me with financial assistance to begin this project, and second, for the Advanced Degree Award in the latter stages, which allowed me time to devote to writing the final draft. Without these funding opportunities it is unlikely that this thesis would ever have materialised. To Paul, thank you for your input towards helping this project finally draw to a close. Although not all your suggestions were helpful (tempting as it was to 'simply download something from the Internet and save myself a lot of time and effort') you certainly helped keep my studies in perspective with the rest of life's ongoing demands. Offers of help along the lines of cooking dinner, hanging out the washing and so on would have been welcomed, however, I begrudgingly acknowledge that practical computing help went someway to contributing to the final product! Finally, thank you Emma. You were two years old when I started this thesis and you helped enormously by ensuring that I never lost track of the most important thing along the way - taking time out to do other things. Admittedly, there were times when I III wished I didn't have to take so much time out to do the other things, but now it is over, I am pleased that I did! IV TABLE OF CONTENTS 1 . IN"TRODUCTION ....................................................................................................... 1 1 . 1 Background ...................... ............................ .......................................................... 1 1 .2 Objectives ..................................................... .......................................................... 2 1 .3 Outline of the Thesis ........ ............................ .......................................................... 3 1 .4 Summary ................................................................................................ . . . ............. 4 2. BLOOD DONATION ........................................ ............................ .............................. 6 2 . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 .2 Blood Donation Behaviour .................................................................................... 7 2.3 Summary ................................................................................................. ............. 29 3. APPROACHES TO PREDICTIN"G BEHAVIOUR ...................... ............................ 32 3 . 1 Introduction .............................................................................................. ............ 32 3 .2 Using Attitude to Predict Behaviour ............ ............................ ............................ 32 3.3 An Alternative Approach to Predicting Behaviour .............................................. 54 3.4 Summary .......................... .................................................................................... 63 4. QUESTIONNAIRE DEVELOPMENT AND PRELIMIN"AR Y RESEARCH ......... 65 4. 1 Introduction .................................................. ............................. ........................... 65 4.2 Designing the TPB Questions .............................................................................. 66 4.3 Designing the Labaw Questions ........................................................................... 77 4.4 Sampling and Survey Methodology ............. ........................................................ 87 4.5 Coding and Analysis .................................... ............................. ........................... 92 4.6 Results .................................................................................................................. 98 4.7 Conclusions ........................................................................................................ 1 08 5 . RESULTS AND DISCUSSION .................................................... .......................... 1 1 2 5 . 1 Introduction ............. ........................................................................................... 1 1 2 5 .2 Sampling and Survey Methodology ................................................................... 1 1 2 5 .3 Coding and Analysis ................................................................ .......................... 1 20 5.4 Results .................................................. .............................................................. 1 2 1 5 .5 Discussion .......................................................................................................... 1 34 5 .6 Summary ............................................................................................................ 1 55 6. SUMMARY AND CONCLUSIONS ...................................................................... 1 56 6. 1 Introduction ...................... .................................................................................. 1 56 6.2 Research Overview .. . . . .. . ...................... .................. ................. ........................... 1 56 6.3 Conclusions ........................................................................................ , . . . . . . . . . . . . . . . 1 58 6.4 Research Limitations ........................... ............................ ............................. ...... 1 65 6.5 Suggestions for Future Research ......... ............................................................... 1 67 6.6 Summary ............................................................................................................ 1 69 7. REFERENCES .......................................... ............................................................... 1 7 1 v TABLE OF TABLES Table 4. 1 Correlations Between Selected TPB Measures (Current Study) ................... 99 Table 4.2 Correlations Between Selected TPB Measures (Giles and Cairns study) . . . . 1 00 Table 4.3 Correlations Between Selected Labaw-Type Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0 1 Table 4.4 Behavioural Intention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 1 02 Table 4.5 Actual Behaviour: TPB Direct Variables ................................................. . .. 1 05 Table 4.6 Actual Behaviour: TPB Indirect Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 06 Table 4.7 Actual Behaviour: Labaw Variables . .. . .. ...................................................... 1 07 Table 5 . 1 Interview Location and Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 3 Table 5.2 Respondents' Reported Donation Behaviour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 20 Table 5.3 Correlations Among Selected TPB Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 22 Table 5 .4 Correlations Among Selected Labaw-Type Measures ................. ................ 1 23 Table 5 .5 Behavioural Intention .............................................................. .................. ... 1 24 Table 5 .6 Behavioural Intention: Combined Model Correlations ..................... .......... 1 27 Table 5 .7 Behavioural Intention: Combined Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 28 Table 5 .8 Actual Behaviour - TPB Direct Variables ... ................................................ 1 29 Table 5.9 Actual Behaviour - TPB Indirect Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 30 Table 5 . 1 0 Actual Behaviour - Labaw Variables ................. ....................................... 1 3 1 Table 5 . 1 1 Actual Behaviour: Combined Model Correlations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 32 Table 5 . 12 Actual Behaviour: Combined ModeL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 33 Table 6 . 1 Predictive Abi lities of the Models Tested ....... ......... . . . ................................. 1 59 Table 6.2 R2 Values for the Two Research Stages .................. . . ......... ....................... ... 1 62 TABLE OF FIGURES Figure 1 Figure 2 Figure 3 Model of The Theory of Reasoned Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Model of The Theory of Planned Behaviour .............................. ................. . 49 Model of Labaw's Approach to Predicting Behaviour ..... . ........................... 78 TABLE OF APPENDICES APPENDICES ................................................................................................... . . ......... 1 84 APPENDIX A: MANA W ATU BLOOD DONOR ANALYSIS ...................... ............ 1 85 APPENDIX B: TPB ELICITATION PROCESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 88 APPENDIX C : INTERVIEWERS' INSTRUCTIONS ................................................ 1 94 APPENDIX D: SURVEY QUESTIONNAIRES ........................ .................................. 200 APPENDIX E: QUESTIONNAIRE CODING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 APPENDIX F: SURVEY DETAILS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 APPENDIX G: SURVEY FEEDBACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 VI