Quantifying the Opportunity Cost of Resident Involvement in Academic Orthopedic Shoulder Arthroplasty: A Matched – Pair Analysis

Background There is minimal work defining the economic impact of resident participation in shoulder arthroplasty. Thus, this study quantified the opportunity cost of resident participation in total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) by determining differences in operative time, relative value units (RVUs)/hour, and RVUs/case. Methods A retrospective analysis of shoulder arthroplasty procedures were identified from the ACS-NSQIP database from 2006 to 2014 using CPT codes. Demographic, comorbidity, preoperative laboratory data and surgical procedure were used to develop matched cohorts. Mean differences in operative time, RVUs/case and RVUs/hour between attending-only (AO) cases and cases with resident involvement (RI) were examined. Cost analysis was performed to identify differences in RVUs generated per hour in dollars/case. Results A total of 1786 AO and 1102 RI cases were identified. With the exception of PGY-3 and PGY-4 cases, RI cases had lower mean operative times compared to AO cases. The cost of RI was highest for PGY-3 ($199.87 per case) and PGY-4 ($9 .2 9) residents with all other postgraduate years providing a cost reduction. Discussion Involvement of residents was associated with shorter operative times leading to a savings of $29.64 per case. Involvement of intermediate-level (PGY-3) residents were associated with increased costs that ultimately decreased as residents became more senior.

The Cyclical Behavior of Unemployment and Wages under Information Frictions

I propose a new mechanism for sluggish wages based on workers’ noisy information about the state of the economy. Wages do not respond immediately to a positive aggregate shock because workers do not (yet) have enough information to demand higher wages. The model is robust to two major criticisms of existing theories of sluggish wages and volatile unemployment, namely, that wages are flexible for new hires and the flow opportunity cost of employment (FOCE) is pro-cyclicality. The model generates volatility in the labor market as well as wage and FOCE elasticities with respect to productivity, consistent with the data. (JEL E24, E32, J24, J31, J63)

CASE STUDY OF A BAKER COMPANY: WHEAT STOCK MANAGEMENT EVALUATION

The goal problem of this work is to propose improvement of wheat inventory management of a bakery, applying the inventory management method “P” and opportunity cost analysis. The study makes historical analysis of the company and proposes the adequacy of the model in order to reduce waste and production inefficiency. The adopted methodology is the case study, because the author does not have direct action during the elaboration of the work. The study shows through the basic calculations of the management model literature “P”, in order to propose the adequacy. The improvement proposal involves new quantities and periodicities of purchase, showing the feasibility of the opportunity cost study, seeking to insert the company's management model to the proposed one.

Anticipative Dynamic Slotting for Attended Home Deliveries

Attended home delivery requires offering narrow delivery time slots for online booking. Given a fixed fleet of delivery vehicles and uncertainty about the value of potential future customers, retailers have to decide about the offered delivery time slots for each individual order. To this end, dynamic slotting techniques compare the reward from accepting an order to the opportunity cost of not reserving the required delivery capacity for later orders. However, exactly computing this opportunity cost means solving a complex vehicle routing and scheduling problem. In this paper, we propose and evaluate several dynamic slotting approaches that rely on an anticipatory, simulation-based preparation phase ahead of the order horizon to approximate opportunity cost. Our approaches differ in their reliance on outcomes from the preparation phase (anticipation) versus decision making on request arrival (flexibility). For the preparation phase, we create anticipatory schedules by solving the Team Orienteering Problem with Multiple Time Windows. From stochastic demand streams and problem instance characteristics, we apply learning models to flexibly estimate the effort of accepting and delivering an order request. In an extensive computational study, we explore the behavior of the proposed solution approaches. Simulating scenarios of different sizes shows that all approaches require only negligible run times within the order horizon. Finally, an empirical scenario demonstrates the concept of estimating demand model parameters from sales observations and highlights the applicability of the proposed approaches in practice.

Comparative Study of Factors Affecting Dependency of Households on Dry Deciduous Forest in Shivpuri, Madhya Pradesh (India)

The rural and tribal communities of Madhya Pradesh’s Shivpuri District depend on forest resources for meeting their domestic energy needs, forest products, and employment. Under Green India Mission, households were randomly selected and surveyed. The data of 61 households from 3 villages of Satanwada range (dry deciduous forest) and 131 households from 4 villages in Pichhore range (dry deciduous scrub forest) was collected through semi-structured questionnaire interviews and direct observation. Generalised Linear Model was used to determine the major factors affecting fuelwood collection. The study revealed the factors affecting the amount of fuelwood collection in Satanwada and Pichhore. Family size of households near to the forest negatively affected the amount of fuelwood collected; opportunity cost of fuelwood collection was lower for them than for families living further away from the forest in Satanwada. In Pichhore, LPG consumption reduced the amount of fuelwood collected, while cow dung complimented the quantity of fuelwood collected. Since the availability of fuelwood was scarce, alternate energy resources became determining factors of the amount of fuelwood collected. In both ranges, the distance of the forest from households had a positive effect on the quantity of fuelwood consumed due to higher opportunity cost and degradation of adjacent forests. The study also revealed a strong correlation between the sampled population percentage of women in villages and the sampled village cattle count. The study also showed the difference of fuelwood collection in Satanwada (8.8 ± 0.6 kg) and Pichhore (6.8 ± 0.4 kg) suggesting that forest degradation correlates with lesser utilisation of forest resources. Hence, the study justifies the need of synergy between public rural provisions of alternative fuel sources with afforestation programs.

Estimating Opportunity Cost as A Tool to Evaluate Water Loss Management of Non-Revenue Water at PDAM Tirta Khatulistiwa

Water loss or Non-Revenue Water (NRW) is a national problem PDAMs, including PDAM Tirta Khatulistiwa. In fact, with a high level of water loss, there is a significant potential loss of income. This study aims to implement opportunity cost calculation as a managerial tool for PDAM Tirta Khatulistiwa in making investment decisions to improve water loss management. This research was conducted by collecting information from financial, managerial, and local government equity participation reports. Then the data reduction is carried out and calculated based on the gross margin, net profit margin, and the opportunity cost. This study indicates that the capital investment provided by the Pontianak City’s government has increased, followed by an increase in the number of consumers. However, it was not followed by an increase in the company’s profit. This is due to the opportunity cost or lost income during the business process amounting to Rp31,218,673,384.64 in 2019 with a potential income to Rp222,663,258,365.00 if it manages to suppress distribution leakage to the level of 20%. This potential income is worthy of consideration for PDAM Tirta Khatulistiwa to start water loss management in the NRW reduction program.