Mark Twain advised: "Buy land, they're not making it anymore." As the world's population increases, the advice may well take on extra significance. As the late Scottish writer Andro Linklater comments in his recent history of land ownership, Owning the Earth , "any realistic scenario of 2050 has to consider how the earth will be owned". The book charts the rise of the theory and practice of a form of private ownership of land that originated in England. Its characteristics are an assertion of individual, exclusive property rights to land. The creation of this system required owners to ride roughshod over other communal, and often informal, claims on the land. Linklater argues that, in many places, the revolution of the past 200 years has been the shift from communal to individual ownership of land. This conception of land ownership gave rise to accurate land surveys, since the new tradability of land demanded exact and objective forms of measurement. The survey of the whole of the land mass of the United States allowed speculators to treat land "simply as a commodity defined by numbers", writes Linklater. Land came to have its own laws of supply and demand. There is a ... tendency for the property-owning class ... to secure political domination The legal system also came to the aid of the new owners in a variety of ways. Linklater comments that through requirements for formal records of land ownership, "paper recruited the power of government to the side of the property owner". Land law is a kind of technology that facilitates the efficient exploitation of the scarce resource that is land by its owners. The benefits of secure private ownership are clear. It provides the incentive for the efficient use of land. Strong property rights also allow land to be used as collateral for loans and so, to this day, the ability to mortgage property is central to the ability of many small businesses to raise the finances that they need. Land becomes much more productive when it is in the hands of people with secure title to it. This is the economic argument for private property. The economic benefit, however, comes at a cost. The English Enclosure Acts, by which common land was made subject to private ownership, were economically efficient but socially devastating. Enclosure involved ignoring the unwritten system of rights and duties concerning land ownership. Linklater argues that the experience had profound psychological effects. The battle between greed and moderation became internalised and so the beginnings of a modern sensibility began to emerge. Politically, the shift to an individualistic form of property ownership played out in two contradictory ways. First, there is a recurrent tendency for the property-owning class in a society to secure political domination to protect its interests. Second, a combination of self-interest and genuine social concern led to restitutionary welfare measures such as the Elizabethan Poor Law enacted in 1601. It is easy to see the contemporary provision of public housing as being partly inspired by such concerns. Linklater's contention is that the need to find ways to give adequate recognition to broader social claims on the land is one that every society has to address. Finding a reasonable solution is not only an ideal but also confers a practical benefit on all, property owner or not. Professor Michael Lower of the Faculty of Law at Chinese University teaches and researches land law