General Report: Causal Uncertainty and Proportional Liability: Analytical and Comparative Report -- I. Introduction -- 1. Meaning and Definition of Proportional Liability in the Project -- 2. Causal Proportional Liability Contrasted with Proportional Liability Among Multiple Tortfeasors Based on Contributory (Comparative) Negligence -- 3. The Aim of This Project -- 4. Structure -- II. Categories of Proportional Liability -- 1. Why Categorize? -- 2. Category A - Uncertain Causes of Past Harm -- A. Sub-category A1 - 'alternative liability' - indeterminate tortfeasors -- B. Sub-category A2 - 'market-share liability' - causally unrelated tortfeasors and victims -- C. Sub-category A3 - 'pollution or drug cases' - indeterminate victims -- D. Sub-category A4 - 'The hard case' -- E. Sub-category A5 - 'lost chances' -- 3. Category B - Indeterminate Parts of Harm -- A. Sub-category B1 - all parts of P's harm were caused by liable Ds -- B. Sub-category B2 - some parts of P's harm were caused by other factors -- 4. Category C - Unrealized Risks with Potential for Future Harms -- 5. Category D - 'Combination Cases' -- III. Policy Considerations -- IV. Burden and Standard of Proof -- V. Category A - Uncertain Causes of Past Harm -- 1. Sub-category A1 - 'Alternative Liability' - Indeterminate Tortfeasor -- A. Analysis -- B. A1 cases in comparison -- 2. Sub-category A2 - 'Market-share Liability' - Causally Unrelated Tortfeasors and Victims -- A. Analysis -- B. A2 cases in comparison -- 3. Sub-category A3 - 'Pollution or Drug Cases' - Indeterminate Victims -- A. Analysis -- B. A3 cases in comparison -- 4. Sub-category A4 - 'The Hard Case' -- A. Analysis -- B. A4 cases in comparison -- 5. Sub-category A5 - The 'Lost Chance' Doctrine -- A. Analysis -- B. A5 cases in comparison.

VI. Category B - Indeterminate Parts of Harm -- 1. Sub-category B1 - Indeterminate Parts of Harm Caused by Tortious Actors -- A. Analysis -- B. B1 cases in comparison -- 2. Sub-category B2 - Indeterminate Parts of Harm Caused by Non-tortious Factors -- A. Analysis -- B. B2 cases in comparison -- VII. Category C - Risks of Future Harm -- 1. Sub-category C1 - Future Harm Uncertain Entirely -- A. Analysis -- B. C1 cases in comparison -- 2. Sub-Category C2 - Extent of Future Harm Uncertain -- A. Analysis -- B. C2 cases in comparison -- VIII. Category D - 'Combination Cases' -- 1. On the meaning of combination cases -- 2. How to cope with 'combination cases' -- IX. Summary and Conclusions -- 1. How to Approach CPL Issues? -- 2. The Relevant Factual Effects of CPL -- 3. Normative Considerations -- 4. On the Cautious Monitored Development of CPL -- 5. On the Comparative Landscape -- 6. On Future Developments -- Categories of Proportional Liability -- Category A - Uncertain Causes of Past Harm -- Sub-category A1 - 'Alternative Liability' - Indeterminate Tortfeasor -- Sub-category A2 - 'Market-share Liability' - Causally Unrelated Tortfeasors and Victims -- Sub-category A3 - 'Pollution or Drug Cases' - Indeterminate Victims -- Sub-category A4 - 'The Hard Case' -- Sub-category A5 - The 'Lost Chance' Doctrine -- Category B - Indeterminate Parts of Harm -- Sub-category B1 - Indeterminate Parts of Harm Caused by Tortious Actors -- Sub-category B2 - Indeterminate Parts of Harm Caused by Non-tortious Factors -- Category C - Risks of Future Harm -- Sub-category C1 - Future Harm Uncertain Entirely -- Sub-category C2 - Extent of Future Harm Uncertain -- Category D - 'Combination Cases' -- Country Reports -- Causal Uncertainty and Proportional Liability in Austria -- I. Standard of Proof.

II. The Discussion of Proportional Liability in Austria -- A. The Starting Point - Multiple Tortfeasors under the ABGB -- B. Alternative Causes -- 1. Alternative External Causes -- 2. Alternative External Causes Competing with Risks within the Victim's own Sphere -- C. Other Instances of Causal Uncertainty -- 1. Alternative Victims -- 2. Minimal Causation -- 3. Loss of a Chance -- 4. Market-Share Liability -- D. The Two Drafts of a Tort Law Reform - One Step Forward and Two Steps Back -- III. The Case Hypotheticals from an Austrian Perspective -- A. Category A - Uncertain Causes of Past Harm -- 1. Sub-category A1 - 'Alternative Liability' - Indeterminate Tortfeasor -- 2. Sub-category A2 - 'Market-share Liability' - Causally Unrelated Tortfeasors and Victims -- 3. Sub-category A3 - 'Pollution or Drug Cases' - Indeterminate Victims -- 4. Sub-category A4 - 'The Hard Case' -- 5. Sub-category A5 - The 'Lost Chance' Doctrine -- B. Category B - Indeterminate Parts of Harm -- 1. Sub-category B1 - Indeterminate Parts of Harm Caused by Tortious Actors -- 2. Sub-category B2 - Indeterminate Parts of Harm Caused by Non-tortious Factors -- C. Category C - Risks of Future Harm -- D. Category D - 'Combination Cases -- IV. Summary -- Causal Uncertainty and Proportional Liability in the Czech Republic -- I. Definition of Proportional Liability -- A. Introduction -- B. Legal Provisions of Substantive Law -- 1. Provisions on Multiple Tortfeasors -- 2. Causation -- 3. Provisions on Proportional Liability -- II. Policy Consideration -- III. Burden of Proof -- A. Legal Provisions -- B. Possible Changes -- IV. Category A - Uncertain Causes of Past Harm -- 1. Sub-category A1 - 'Alternative Liability' - Indeterminate Tortfeasor.

2. Sub-category A2 - 'Market-share Liability' - Causally Unrelated Tortfeasors and Victims -- 3. Sub-category A3 - 'Pollution or Drug Cases' - Indeterminate Victims -- 4. Sub-category A4 - 'The Hard Case' -- 5. Sub-category A5 - The 'Lost Chance' Doctrine -- V. Category B - Indeterminate Parts of Harm -- 1. Sub-category B1 - Indeterminate Parts of Harm Caused by Tortious Actors -- 2. Sub-category B2 - Indeterminate Parts of Harm Caused by Non-tortious Factors -- VI. Category C - Risks of Future Harm -- 1. Sub-category C1 - Future Harm Uncertain Entirely -- 2. Sub-category C2 - Extent of Future Harm Uncertain -- Causal Uncertainty and Proportional Liability in Denmark -- Causal Uncertainty and Proportional Liability in England and Wales -- I. Introduction -- Meaning of 'Proportional Liability' -- II. Proportional Liability: The Fairchild Exception -- A. Starting Points -- B. Orthodox Approach to Alternative Causes -- C. Fairchild and beyond -- III. The Categories of Proportional Liability -- A. Alternative Liability (Unidentified Tortfeasor) -- B. 'Market-Share Liability' (A Closed Set of Tortfeasors and Victims) -- C. Pollution and Drug Cases (Unidentified Victim) -- D. Increased Risk -- E. The 'Lost Chance' Doctrine -- F. Certain Causation - Uncertain Extent (Only Tortious Causes) -- G. Certain Causation - Uncertain Extent (Tortious and Non-Tortious Causes) -- H. Causal Uncertainty as to Future Harm -- IV. Concluding Remarks -- Causal Uncertainty and Proportional Liability in France -- I. Introduction -- II. Burden and Standard of Proof -- III. Category A - Uncertain Causes of Past Harm -- 1. Sub-Category A4 - A5: The 'Hard Case' and Lost Chances -- 2. Sub-category A1 - 'Alternative Liability' - Indeterminate Tortfeasor.

3. Sub-category A3 - 'Pollution or Drug Cases' - Indeterminate Victims -- 4. Sub-category A2 - 'Market-share Liability' - Causally Unrelated Tortfeasors and Victims -- IV. Category B - Indeterminate Parts of Harm -- V. Category C - Risks of Future Harm -- 1. Sub-category C1 - Future Harm Uncertain Entirely -- 2. Sub-category C2 - Extent of Future Harm Uncertain -- Causal Uncertainty and Proportional Liability in Germany -- I. Definition of Proportional Liability -- II. Categories of Proportional Liability -- III. Policy Considerations -- 1. Deterrence -- 2. Justice/Fairness -- 3. Reduction of Administrative Costs -- 4. Further Policy Considerations -- IV. Burden of Proof -- 1. In General -- 2. Standard of Proof -- V. Category A - Uncertain Causes of Past Harm -- 1. Sub-category A1 - 'Alternative Liability' - Indeterminate Tortfeasor -- 2. Sub-category A2 - 'Market-share Liability' - Causally Unrelated Tortfeasors and Victims -- 3. Sub-category A3 - 'Pollution or Drug Cases' - Indeterminate Victims -- 4. Sub-category A4 - 'The Hard Case' -- 5. Sub-category A5 - The 'Lost Chance' Doctrine -- VI. Category B - Indeterminate Parts of Harm -- 1. Sub-category B1 - Indeterminate Parts of Harm Caused by Tortious Actors -- 2. Sub-category B2 - Indeterminate Parts of Harm Caused by Non-tortious Factors -- VII. Category C - Risks of Future Harm -- 1. Sub-category C1 - Future Harm Uncertain Entirely -- 2. Sub-category C2 - Extent of Future Harm Uncertain -- VIII. Category D - 'Combination Cases -- IX. Conclusions -- 1. In General -- 2. The Relevant Factual Effects of Proportional Liability -- (a) Gainers and Losers -- (b) Effect on Incentives -- (c) Number of Suits -- (d) Costs of Suits -- (e) Informational Difficulties -- (f) Distribution of Probabilities -- (g) Degree of Fault -- (h) Degree of Uncertainty.

3. Policy Considerations.