1 Introduction 1
A. Thematic Outline 2
B. Chapter Summaries 2
Part Ⅰ The Foundations 7
2 Introduction to the Defence of Disimpoverishment 9
A. Introduction 9
B. Questions in Unjust Enrichment 9
C. Definition 10
D. Change of Name 11
1. History of ‘Passing on’ 12
2. Errors of Exclusion 12
3. Errors of Inclusion 14
（a） Source of the Errors 14
（b） Problems with Errors 15
（c） Example of the Errors 16
E. Another Problem with Pseudonyms 17
F. Triggering the Defence of Disimpoverishment 19
1. Not Restricted to Cases of Unlawful Taxation 19
2. Anticipatory Disimpoverishment 20
G. Assumptions 20
1. The ‘Windfall’ Assumption 20
（a） The Defendant will Also Receive an Undeserved Windfall 20
（b） The Role of Third Parties 21
2. Causation 21
H. Taxation Agents 23
I. Burden of ProoF 25
1. Onus is on the Claimant 25
2. Onus is on the DefendanT 25
3. Is Reversal of the Onus of Proof Apparent but Not Real？ 27
（a） A Presumption of DisimpoverishmenT 28
（b） It is Sufficient to Raise，but not Prove，the Defence 28
4. Where should the Burden Lie？ 29
J. Judicial Responses to DisimpoverishmenT 30
1. Acceptance of the Defence at LaW 31
（a） Accept at Law and on the Facts 31
（b） Accept at Law but Reject on the Facts 31
2. Rejection of the Defence at LaW 31
3. Qualified RejectioN 32
K. Conclusion 34
3 Common Law Cases on the Defence of DisimpoverishmenT 35
A. IntroductioN 35
B. England 35
1. Linz v Electric Wire Company of Palestine Ltd 35
2. The Swaps Cases 36
（a） The Decisions 36
（b） Are the Decisions Binding？ 39
3. Woolwich Equitable Building Society v Inland Revenue CommissionerS 40
4. Banque Belge Pour L’etranger v Hambrouck 41
C. Australia 43
1. Mason v New South WaleS 43
2. Commissioner State Revenue （Victoria） v Royal Insurance Australia LtD 44
3. Roxborough v Rothmans Pall Mall 46
D. CanadA 47
1. Acceptance at Law and on the Facts 47
（a） Unlawful Demand by a Public Authority 47
（b） MistakE 48
2. Acceptance at Law but Rejection on the Facts 49
（a） Unlawful Demand by a Public Authority 49
（b） MistakE 50
3. Rejection at Law 50
E. United States of America 52
1. Rejection at Law 52
2. Qualified RejectioN 57
3. Acceptance at Law 59
F. Conclusion 62
4 Statutory Defence of Disimpoverishment 63
A. IntroductioN 63
B. The Defence of Unjust EnrichmenT 63
1. Relevant Statutory ProvisionS 63
2. The Meaning of ‘Unjustly Enrich’ 64
（a） The Meaning of ‘Enrichment’ 65
（b） The Meaning of ‘Unjust’ 65
3. Correlation with the Defence of DisimpoverishmenT 65
C. Operation of the Unjust Enrichment Defence 66
1. Condition #1： The Claimant Must ‘Pass on’ the Cost of the Tax 67
2. Condition #2： The Claimant Must Avoid Any Loss 69
（a） No Change in Price 70
（b） The ‘Price Taker’ Argument 71
（c） Counter factual Argument #1： Prices would have Increased AnywaY 75
（d） Counter factual Argument #2： Revenue would have Increased 77
（e） Increase in Price Not Matched by an Increase in Revenue 78
（f） Potential Substitutability of Profitable Products 79
3. Condition #3： Recovery Must ‘Unjustly Enrich’ the ClaimanT 80
4. Conclusion 80
D. Recovery for Third Parties of Overpaid VAT 81
1. Direct Recovery by Third Parties 81
2. Claimant Recovering for Third Parties 81
3. Conclusion 84
E. Influence of European JurisprudencE 85
1. Three General Propositions from the ECJ 85
2. Three Specific Propositions from the ECJ 86
F. Conclusion 86
1. Some Specific ObservationS 86
2. Implications for this Book 87
Part Ⅱ ‘At The Expense Of’ 89
5 What Might ‘At the Expense of’ Mean？ 91
A. IntroductioN 91
B. Two Interpretations of ‘at the Expense of’ 92
C. The Meaning of ‘Loss’ 93
1. ‘Loss’ Meaning ‘Detriment’ 93
（a） Pecuniary DetrimenT 93
（b） Non-pecuniary Detriment 95
2. ‘Loss’ Meaning ‘Deprivation’ （of a Right） 101
（a） Examples in the Case Law of ‘Loss’ Meaning‘Deprivation of A Right’ 102
（b） Should a ‘Deprivation of a Right’ Constitute a ‘Loss’？ 103
3. ‘Loss’ Meaning ‘Opportunity Forgone’ 105
D. Loss and RestitutioN 107
1. Corresponding LosS 107
（a） Only ‘Some’ Loss is Necessary 107
（b） A ‘Corresponding’ Loss is Required 107
（c） The Preferred Interpretation of whether a LossMust be CorrespondinG 108
2. Initial or Ultimate Loss？ 109
E. The Meaning of ‘From’ 109
1. Things and Services： What Exactly Comes from the Claimant？ 110
（a） ThingS 110
（b） Services 111
F. Differences between ‘From’ and ‘Loss’ 112
G. Conclusion 112
H. AddenduM 113
6 What do the Cases say ‘At the Expense of Means？ 115
A. IntroductioN 115
1. Scope and Purpose 115
2. StructurE 116
3. OutcomE 116
B. Situation 1： ‘Gain’ Exceeds ‘Loss’ at the Moment of Receipt 116
1. England 117
（a） Re BHT （UK） Ltd 117
（b） Greenwood v BennetT 118
（c） Hambly v TrotT 119
（d） Banque Financiere De La Cite v Parc （Battersea Ltd） 121
（e） BP Exploration Co （Libya） v Hunt （No 2） 122
（f） Debt Discharged at Less Than Full Value 125
（g） Necessitous InterventioN 127
2. Australia 129
（a） InterestAwardS 129
3. Canada 132
4. United States of America 133
5. Conclusion 134
C. Situation 2： ‘Gain’ Increases After Receipt 135
1. England 135
（a） The Decisions 135
（b） Reasons for JudgmenT 136
（c） The True State of Affairs in FC Jones and Foskett v Mckeown？ 137
（d） Implications for the ‘at the Expense of RequiremenT 138
2. Australia 138
3. United States of America 140
D. Conclusion 142
7 What should ‘at the Expense of Mean？ 143
A. IntroductioN 143
1. The InquirY 143
2. Structure and OutcomE 143
B. The Problem Restated： The Status Quo Ante cannot be RestoreD 144
1. Restitution when Loss and Gain Correspond 144
（a） Pre-exchange EquilibriuM 145
（b） Identification of the Parties 145
（c） The Appropriate Response is Restitution 145
2. Conclusion 146
C. Four Conceptions of What ‘At the Expense of MeanS 146
D. Whenever Loss and Gain Do Not Equate 148
1. The Work is Done ElsewherE 148
2. The Meaning of ‘Restitution’ 149
3. Windfalls 150
4. Conservation of Judicial Resources 151
（a） Are the Parties Equally Undeserving？ 151
（b） What If the Claimant Incurs Some Loss？ 152
（c） Difficulty in Proving Loss 152
5. Presumption of Self-reliance 153
E. ‘Gain’ Exceeds ‘Loss’at the Moment of Receipt 154
1. Symmetry with Restitution for Wrongs 154
（a） Restitution Versus Disgorgement for Wrongs 154
（b） Restitution for Wrongs and Unjust Enrichment 154
（c） The Implications of Symmetry 155
（d） Wrongs and Unjust Enrichment： Different Events 156
2. Corrective Justice and Kantian Rights 157
（a） Corrective Justice on Aristotle’s Terms 157
（b） Corrective Justice Through a Kantian Lens 158
（c） No IntenT 160
（d） Policy-based Restitution 161
（e） When Gain and Loss Do not Equate 161
3. ConclusioN 163
F. ‘Gain’ Increases After ReceipT 163
1. IntroductioN 163
（a） The Issue and the Perspectives 163
（b） Four Preliminary Matters 164
2. What Has Come At the Expense of the Claimant？ 165
（a） The Normative Position 166
（b） Unjust Enrichment at the Expense of the Defendant 167
（c） Directness 168
（d） The Transfer 169
（e） Symmetry （of Risk） with the Defence of DisenrichmenT 169
3. ConclusioN 171
G. Conclusion 171
Part Ⅲ Other Reasons to Reject or Accept the Defence of Disimpoverishment 173
8 Other Arguments for Accepting the Defence of DisimpoverishmenT 175
A. IntroductioN 175
B. False Bases for Accepting the Defence 175
1. Inflation Reduction 175
2. Third Parties Incur Two Losses 177
3. Symmetry with the Defence of DisenrichmenT 179
4. Litigation Chains 181
（a） Limited ApplicatioN 181
（b） In Support of the Defence of DisimpoverishmenT 182
（c） Unsupported Fears and Conclusions 182
5. Protection of Government Finances 183
（a） Reasons for Refusing Restitution 184
（b） A Nuanced Response 185
（c） Reasons for Awarding Restitution 185
C. A Legitimate Basis for Rejecting the Defence 187
1. The Claimant will Receive a Windfall 187
（a） Receipt via An Unimpeachable Contract or Gift 188
（b） Receipt via an Unjust Enrichment at the Expense of a Third PartY 189
D. Conclusion 190
9 Other Arguments for Rejecting the Defence of Disimpoverishment 191
A. IntroductioN 191
B. False Bases for Rejecting the Defence 191
1. Symmetry with Tort Law 191
2. Undertaking to Pass-back 193
（a） Rejecting the DefencE 193
（b） True Rejection？ 193
3. It is Only a Complete，Not Partial，Defence 194
C. Potential Bases for Rejecting the Defence 194
1. Problems of ProoF 194
（a） The ProblemS 195
（b） Examination of the Problems 195
（c） Proof of ImpoverishmenT 198
（d） ConclusioN 202
2. Recovery Based on Economic Assumptions should not be PermitteD 202
3. Unlawful Demands for TaX 204
D. Three Reasons for Rejecting the Defence 207
1. Res Inter Alios Acta Alteri Nocere Non DebeT 207
2. The Claimant’s Defective Transfer 208
3. The Ideal Corrective Justice Solution will not be Attained 209
（a） Problems with Attaining Corrective Justice when the Defence is UphelD 209
（b） What are the Alternatives？ 211
E. Conclusion 218
Part Ⅳ Third PartieS 219
10 Third PartieS 221
A. IntroductioN 221
B. When Can an Action be Brought Against a Claimant？ 221
1. Third Party v Claimant 221
2. Parens PatriaE 222
C. Class ActionS 223
1. What is a Class Action？ 224
2. What are Some of the Advantages of Class Actions？ 224
3. Two IllustrationS 225
（a） Javor v State Board of Equalization 225
（b） Cauvin v Phillip Morris 226
（c） ConclusioN 228
D. Recovery of Overpaid Tax by a Third Party （from the Claimant） 228
1. The Issue 228
（a） An IllustratioN 228
（b） The Purpose of this Inquiry 229
2. Is Restitution within a Valid Contract Permitted？ 230
（a） Composite Charge 230
（b） Itemized Charge 231
（c） ConclusioN 234
3. Is Restitution within a Valid Contract Justified？ 234
（a） The Item is Severable and Not Negotiated 234
（b） Analysis of the Beatson and Birks Perspective 235
E. Conclusion 242
11 ConclusioN 245
A. The Problems Restated 245
B. The Conclusions ReacheD 245
1. A Change of Name 245
2. Three Possible Responses，Not Two 246
3. The Meaning of At the Expense of’ 246
4. Other Arguments For and Against the Defence 247
5. Implications for the Statutory Defence 248
6. Third Party Claims 248
C. RestatemenT 249
BibliographY 251
Index 257