Richard Epstein recommends something rather close to a regime of Lockean libertarian rights on the ground that compliance with this regime of rights is utility maximizing (increases aggregate well-being of persons) over the long run (Epstein 1995: chapter 1). Epstein himself is doubtful of interpersonal utility comparison, so he tends to favor policy moves that are Pareto improvements, improving someone's utility while reducing no one's. Still, one might countenance interpersonal comparison and try to defend Lockean libertarian rights on aggregative utility-maximizing grounds. The Epstein regime of rights is only a rough approximation of a strict Lockean libertarian regime, for the former approves utility-promoting curtailment of individual rights. For example, in an Epstein but not a strict Lockean regime, a hiker caught in a blizzard in the mountains who stumbles upon a privately owned cabin may trespass and use the cabin without prior permission of the owner provided compensation is paid for any damage done to the cabin and its provisions. But Epstein holds that enforcement of nondiscrimination norms and equality of opportunity would tend to lessen not promote people's long-run utility. As this formulation suggests, Epstein is concerned with the question, what rules and norms should be enforced by force of law. As against the simple rule that permits all and only deals that elicit the voluntary consent of the participants, the rule forbidding discrimination is costly to administer and enforce, charges of discrimination being easy to make and difficult to prove. According to Epstein, competitive markets pressure people to do what is cost-effective, which generally means hiring the most qualified applicant and selling to any willing customer who is able to pay.