This paper studies the random walk in a general time series setting that allows for weakly dependent and heterogeneously distributed innovations. It is shown that simple least squares regression consistently estimates a unit root under very general conditions in spite of the presence of...

This is a proposal for the application of discrete linear programming to the typical job shop scheduling problem -- one that involves both sequencing restrictions and also non-interference constraints for individual pieces of equipment. Thus far, no attempt has been made to establish the...

Social security system old age insurance systems are devices for the sharing of income risks of elderly people with others. Risks can be shared intergenerationally (with the young of the same country), intragenerationally (with other elderly of the same country) or internationally (with...

We build a model of competitive pooling, which incorporates adverse selection and signalling into general equilibrium. Pools are characterized by their quantity limits on contributions. Households signal their reliability by choosing which pool to join. In equilibrium, pools with lower quantity...

We present a signalling model, based on ideas of Phillip Nelson, in which both the introductory price and the level of directly "uninformative" advertising or other dissipative marketing expenditures are choice variables and may be used as signals for the initially unobservable quality of a...

This paper considers the problem of choosing the number of bootstrap repetitions B for bootstrap standard errors, confidence intervals, and tests. For each of these problems, the paper provides a three-step method for choosing B to achieve a desired level of accuracy. Accuracy is measured by the...