A Tractable Model of Search on the Job and Aggregate Fluctuations
In this paper, we develop a tractable model of the labor market featuring on-the-job search and aggregate fluctuations.
Repeated Moral Hazard with Worker Mobility via Directed On-the-Job Search
I develop a model of dynamic employment contracts by integrating an optimal contracting problem into an equilibrium search framework. The proposed framework enables us to analyze the interaction between the contracting problem and the endogenously evolving outside environment via worker mobility, and I characterize the optimal long-term wage contract as well as the optimal incentive compatible effort-tenure profile. The optimal contract exhibits an increasing wage-tenure profile for two reasons: 1) it induces the workers to be more likely to stay in their current contracts, and 2) it can induce the workers to make efforts when the current up-front wages cannot. The optimal incentive-compatible effort also has an increasing profile due to an interaction between 1) the workers' fear of losing their jobs, and 2) their incentive to obtain better outside offers. I then show the existence of an equilibrium. The equilibrium inherits the ``block recursivity'' developed by Shi (2008) and Menzio and Shi (2008); that is, individuals' optimal decisions and optimal contracts are independent of the distribution of workers.
CLINICAL TRIALS OF THE ABDOMINAL LEFT VENTRICULAR ASSIST DEVICE (ALVAD): PROGRESS REPORT.
An abdominal left ventricular assist device (ALVAD) is undergoing controlled clinical trials in our institution. The ALVAD is pneumatically-actuated, synchronously or asynchronously with an external console and is interposed between the apex of the left ventricle and the infrarenal abdominal aorta. It is an order of magnitude more effective than conventional intraaortic balloon pumping. Thus far, we have implanted this pump in 21 patients (15 males and six females). The average age has been 50. The duration of cardiopulmonary bypass with intensive pharmacologic support and IABP until ALVAD implantation has been nearly 4 hours. The plasma hemoglobins prior to ALVAD implantation have averaged 168 mg%. The platelet counts at implantation have averaged 68,000 mm(3). The average duration of ALVAD support has been in excess of one day and the longest trial extended for one week. We have been able to remove the pump after ventricular recovery in two instances and effected cardiac allografting in one instance of ALVAD dependency. We have found that (1) the profoundly depressed left (and right) ventricles can recover if totally supported with this device; (2) the device can function in the presence of ventricular fibrillation and/or standstill; (3) the device can effectively replace both left and right ventricular function in the presence of normal pulmonary vascular resistance and microcirculatory hemodynamics; and (4) in the presence of impending multiple organ failure, procrastination in use is to be avoided.