No abstract

The primary issue addressed in this research is how to schedule clients as they call for appointments, without knowing which "types" of clients will call at a later time. The main goal is to compare various scheduling rules in order to minimize the waiting time of the clients as well as the idle time of the service provider. Interviews with receptionists verified that they have knowledge regarding differences between clients' service time characteristics. This information is used both to differentiate between clients and to develop various scheduling rules for those clients. A simulation model of a dynamic medical outpatient environment is developed based on insight gained from the interviews and from prior research.Two decision variables are analyzed ("scheduling rule" and "position of appointment slots left unscheduled for potential urgent calls") while two environmental factors are varied ("expected mean of the clients' service time", and "expected percentage of clients with low service time standard deviation compared to those with high service time standard deviation"). This resulted in 30 combinations of decision variables, each tested within 15 combinations of environmental factors. By using multiple performance measures, it is possible to improve considerably on some of the "best" rules found in the current literature. The "best" decisions depend on the goals of the particular clinic as well as the environment it encounters. However, good or best results can be obtained in all cases if clients with large service time standard deviations are scheduled toward the end of the appointment session. The best positioning of slots left open for urgent clients is less clear cut, but options are identified for each of a number of possible clinic goals.

We investigate geographic income shifting by 191 U.S. multinational corporations in response to worldwide changes in tax rates during 1984-90. Between 1984 and 1986, the United Kingdom reduced corporate tax rates from a maximum of 45% to 35%, and in 1985 France rednced rates from 50% to 45%. Following these reductions in European rates, the United States reduced top corporate tax rates from 46% to 34%

This paper examines income shifting of U.S. multinational companies over the past two decades. Domestic and foreign policy makers are increasingly concerned with the effect of income shifting on dwindling tax revenues, however, extant research on income shifting by U.S. multinational enterprises is mixed. We address the disconnect between the academic literature and the policy maker's perceptions by examining the extent of multijurisdictional income shifting by U.S. multinational companies. We directly address conflicting results in extant literature and show that using either multiperiod proxies or instrumental variables overcomes weaknesses of annual proxies in this setting. Our tests show that U.S. companies have become more active at shifting income out of the United States as the regulatory costs of shifting have changed. Holding tax rate differences between U.S. and foreign jurisdictions constant, our empirical estimates suggest that our sample of 380 corporations with low average foreign tax rates collectively shifts approximately $10 billion of additional income out of the United States annually during 2005-2009 relative to 1998-2002 due to varying regulatory costs of shifting.

Using confidential data from the Internal Revenue Service on who signs a corporation's tax return, we investigate whether the party primarily responsible for the tax compliance function of the firm—the auditor, an external non-auditor, or the internal tax department—is related to the corporation's tax aggressiveness. We report three key findings: (1) firms preparing their own tax returns or hiring a non-auditor claim more aggressive tax positions than firms using their auditor as the tax preparer; (2) auditor-provided tax services are related to tax aggressiveness even after considering tax preparer identity, which supports and extends prior research using tax fees as a proxy for tax planning; and (3) Big 4 tax preparers, in particular, are linked to less tax aggressiveness when they are the auditor than when they are not the auditor. Our findings help policymakers and researchers better understand an important feature of tax compliance intermediaries; particularly, how the dual role via audits is related to observable corporate tax outcomes.