The Change of Position Defence

1. Introduction and Overview A Introduction B The Change of Position Defence (1) A Core Case (2) The Four Main Areas of Doubt (a) The Reliance Issue (b) The Fault Issue (c) The Ambit of Operation Issue (d) The Rationale Issue C Underlying Assumptions (1) Introduction (2) The Nature of Unjust Enrichment (3) Restitution and Unjust Enrichment (4) A Fusionist Approach D Methodology and Overview (1) Introduction (2) Part One—Foundations (3) Part Two—Definition (4) Part Three—Ramifications Part One: Foundations 2. Lessons from Estoppel by Representation A Introduction B Elements of Estoppel by Representation (1) Representation (2) Reliance (a) The Meaning of Reliance (b) The Role of Reliance as a Causal Requirement (c) The Applicable Test of Causation (d) Proving Reliance (e) A Residual, Evidential Role for the 'But For' Test. (f) The Normative Significance of Reliance (g) Lessons for the Change of Position Defence (3) The 'Reasonableness' Requirement (a) The Defendant's Reliance must be Reasonable (b) The Standard of Reasonableness and its Relationship to Good Faith (c) The Function of the Reasonableness Requirement (d) Lessons for the Change of Position Defence (4) Detriment (a) The Meaning of Detriment (b) The Time for Assessing the Detrimental Change of Position (c) Detrimental Changes of Position include Omissions and Non-pecuniary Changes (d) The Change of Position must be Irreversible (e) Lessons for the Change of Position Defence C Bars to the Defence (1) Defendant at Fault in Inducing the Representation (2) Defendant in Breach of Duty (3) Illegality D Conclusion 3. Lessons from the Defence of Payment Over by an Agent A Introduction B The Requirement of Payment Over C Notice D Bars to the Defence E Conclusion 4. Lessons from Rescission A Introduction B Restitutio in Integrum (1) Rescission and the Requirement of Restitutio in Integrum (2) The Requirement of Counter-restitution (a) Rationale (b) Elements and Operation (c) Application of the Two Claims Approach to Rescission Cases (3) The Defendant's Changes of Position (a) Change by Exchange (b) Independent Changes in the Received Benefit (c) Defendant-instigated Changes of Position (4) The Claimant's Changes of Position (a) Independent Changes in the Received Benefit (b) Claimant-instigated Changes of Position (c) An Irreconcilable Tension? C Conclusion (1) Rationale (2) Elements (3) Ambit of Operation Part Two: Definition 5. Primary Elements A Introduction B Elements (1) A Detrimental Change of Position (a) Detriment as 'Disenrichment' (b) Detriment as 'Irreversibility' (c) The Irreversibility Approach is to be Preferred (d) Proving the Irreversible Change of Position (2) Causation (a) Introduction (b) But-for Causation in Cases of Independent Changes of Position (c) Good Faith in Cases of Independent Changes of Position (d) Reliance in Cases of Defendant-instigated Changes of Position (e) Reliance must be Reasonable (f) Anticipatory Changes of Position (g) Proving Causation (3) The Impact of Third Parties C Conclusion 6. Fault as a Bar to the Defence A Introduction B Wrongdoers C Duress and Undue Influence D The Innocent Inducer E Illegality and Legal Stultification F Fault in the Defendant's Change of Position G Conclusion 7. Ambit of Operation A Introduction B Application to Claims in Unjust Enrichment (1) Mistake (2) Duress and Undue Influence (3) Failure of Consideration (4) No Intention to Benefit (5) Policy-motivated Unjust Factors (6) Cases of Proprietary Restitution C Application to Claims outside Unjust Enrichment D Conclusion 8. Rationale A Introduction B Disenrichment C Autonomy D Security of Receipt E A Harm-based Rationale F A Mixed Rationale of Protection and Prophylaxis G Conclusion 9. Conclusion Part Three: Ramifications 10. Ramifications A Introduction B Estoppel by Representation C Payment Over and Ministerial Receipt D Restitutio in Integrum E Good Consideration F Bona Fide Purchase G Statutory Change of Position Defences H Conclusion