ersonal property the available forms of property rights are more limited, given the nature of movables and accounts receivable Merrill and Smith argue that the numerus clausus is the expression of an optimal standardization'of property rights. The economic benefits of a new property right must outweigh the costs for third parties to become informed about this new right. In their view, the customising of property rights should, for several reasons, be done by the legislature and not by courts. The legislature may give rules which can be clear, universally applicable, comprehensive, stable, prospective and it may take into account whether and, if so, how implicit compensation should be given to those affected by changes in property rules. 32 Hansmann and Kraakman disagree with the analysis offered by merrill and Smith. 3 They argue that property rights are characterised not, as Merrill and Smith argue, by being ood against the whole world but by being enforceable against subsequent transferees of other rights in an asset. Furthermore, they argue that the numerus clausus doctrine as it, in their view, exists in the common law is not about standardisation, but about regulation of the types and degree of notice required to establish different types of property rights.34 The purpose of regulation is not that third parties are given information, but to enable third parties to verify ownership of the rights offered for conveyance. In this verification process, property exception that a partitioning of property rights across more than one owner is enforceable r o law assumes that all property rights in a given asset are held by a single owner, subject to there has been adequate notice of that partitioning to persons whom it might affect " 35The utility of the partitioning and the costs of giving notice d man, is aimed at weighing the IV Towards a numerus quasi-clausus or standardisation of property rights? It seems to me that the approach taken by merrill and Smith, more than the analysis offered by Hansmann and Kraakman, comes very close to how a civil property lawyer looks at the content, historical background and justification of the numerus clausus doctrine. Hansmann and Kraakman seem to suggest that they do not accept a strict distinction between rights in world, but merely between a person and a certain category of other persons. This latte the personam- which only exist between two or more specific parties-and rights which are good gainst the world. In their view, a right can also be absolute if it is not bind ing against pproach is more of a common law than of a civil law nature. In the words of Lawson and Rudde English lawyers have always been accustomed to classifying interests in land in terms of the time for which they could endure. Leases were easily fitted into this percept ion, although they grew up Ibid., pp 38 ff. Ibid., pp. 58 ff. They conveniently summarise the position of Mermill and Smith and contrast it with their own approach in the first pages of their paper. Hansmann and Kraakman, " Property, Contract and Verification,p Ibid., pp. I f. Ibid. pp. 21 ff.personal property the available forms of property rights are more limited, given the nature of movables and accounts receivable. Merrill and Smith argue that the numerus clausus is the expression of an ‘optimal standardization’ of property rights. The economic benefits of a new property right must outweigh the costs for third parties to become informed about this new right.31 In their view, the customising of property rights should, for several reasons, be done by the legislature and not by courts. The legislature may give rules which can be clear, universally applicable, comprehensive, stable, prospective and it may take into account whether and, if so, how implicit compensation should be given to those affected by changes in property rules.32 Hansmann and Kraakman disagree with the analysis offered by Merrill and Smith.33 They argue that property rights are characterised not, as Merrill and Smith argue, by being good against the whole world, but by being enforceable against subsequent transferees of other rights in an ‘asset’. Furthermore, they argue that the numerus clausus doctrine as it, in their view, exists in the common law is not about standardisation, but about ‘regulation of the types and degree of notice required to establish different types of property rights’.34 The purpose of regulation is not that third parties are given information, but to enable third parties to verify ownership of the rights offered for conveyance. In this verification process, property law assumes that ‘all property rights in a given asset are held by a single owner, subject to the exception that a partitioning of property rights across more than one owner is enforceable if there has been adequate notice of that partitioning to persons whom it might affect.’35 The cost-benefit analysis, as defended by Hansmann and Kraakman, is aimed at weighing the utility of the partitioning and the costs of giving notice.36 IV Towards a numerus quasi-clausus or standardisation of property rights? It seems to me that the approach taken by Merrill and Smith, more than the analysis offered by Hansmann and Kraakman, comes very close to how a civil property lawyer looks at the content, historical background and justification of the numerus clausus doctrine. Hansmann and Kraakman seem to suggest that they do not accept a strict distinction between rights in personam - which only exist between two or more specific parties - and rights which are good against the world. In their view, a right can also be absolute if it is not binding against the world, but merely between a person and a certain category of other persons. This latter approach is more of a common law than of a civil law nature. In the words of Lawson and Rudden: . . . English lawyers have always been accustomed to classifying interests in land in terms of the time for which they could endure. Leases were easily fitted into this perception, although they grew up 31 Ibid., pp. 38 ff. 32 Ibid., pp. 58 ff. 33 They conveniently summarise the position of Merrill and Smith and contrast it with their own approach in the first pages of their paper. 34 Hansmann and Kraakman, ‘Property, Contract and Verification’, p. 1. 35 Ibid., pp. 1 f. 36 Ibid., pp. 21 ff