Fig. 2

BT offer groups. (a) BT balance transfer, PR promotional rate (%), FFL fixed-for-life rate (%), PD promotional duration (months). (b) The short-term finance (payment, spending, and ∆debt) is not significantly impacted by PD and fee. ∆debt represents the difference of debt between every 2 months. Debt is a stock variable that is accumulated balance after BT campaign. Thus, ∆debt is the new debt level in every month, which is used as a dependent variable in this study. There are three types of debt, later, in this study: (1) ∆CCC balance which represents the change of balance in RBS bank. (2) ∆EFX balance represents the change of balance from Equifax bureau. (3) ∆PB balance represents the change of balance with high interest rates calculated by RBS bank itself. Therefore, two interest rates are key parameters for this study. (c) Consumers tend to behave according to different lengths of PD, especially at the end of PD. Thus, the BT offer with PD = 6 months and PD = 12 months is separated in this study. (d) The offers with PD = 12 months only contain fee = $60 or $75. The offers with PD = 6 months contain fee = $0 or $60 or $75. Then, the offers with PD = 6 months and fee = $0 are separated out in order to compare effect of offer at the same level of fee. (e) Comparing the baseline Group A, Group B contains offers that have longer PD with the same fee. Group C contains offers that have fewer fees with the same PD. Therefore, Groups B and C are better than Group A in terms of offers for consumers