ABSTRACT
Capital investment by motor carriers in new trucks and trailers is essential for the effective and efficient operation of supply chains. Strong evidence exists that motor carriers' capital investment is positively correlated with truckload spot prices. This article explores whether the onset of the COVID-19 pandemic moderated the relationship between spot prices and capital investment by motor carriers. We theorize that the onset of the COVID-19 pandemic muted the relationship between spot prices and investment in trucks to a greater degree than it muted the relationship between spot prices and investment in trailers. We attribute this to the COVID-19 pandemic creating tremendous uncertainty about the availability of truck drivers, which made investing in trucks less attractive than investing in trailers that do not require additional labor. To test our theory, we assemble a time series dataset that combines proprietary and public data from several sources. Econometric estimates corroborate our predictions and are robust to instrumental variable estimation to assuage concerns about endogeneity of spot prices. We explain the implications of our findings for theory and practice. Copyright © 2022 The Pennsylvania State University, University Park, PA
ABSTRACT
Purpose : We sought to analyze the changes in clinical care following the restrictions that were implemented in Massachusetts in response to COVID-19 pandemic as well as to depict the visual outcomes in patients receiving intravitreal injections as part of a treatment regimen for either exudative age-related macular degeneration (AMD), diabetic retinopathy (DR), central or branch retinal vein occlusion (CRVO, BRVO). Methods : A retrospective analysis of the intravitreal injection clinics of three retina specialists at Massachusetts Eye and Ear from December 2019 to June 2020 was performed. Demographic data of patients with either wet AMD, DR, CRVO or BRVO were collected. Descriptive statistics were used to quantitatively summarize the features of our cohort and box plots to illustrate the spread and differences of visual acuity among groups over time. Results : A total of 1,086 visits were scheduled within this period and more than a quarter of these visits were not completed [801 (74%) completed vs 285 (26%) cancel or no show;p=0.000]. The mean age of our cohort was 72.5±13.2 years (males: 72.48±13.2;females: 74±12.4;p=0.0524). Out of 259 cancel visits, 240 visits (93%) were canceled by the patients and 19 visits (7%) by the provider/institution (p=0.000). There was no significant difference in the appointment status (completed, cancel, no show) among males and females, among different providers, or diagnoses (p=0.225, p=0.131 and p=0.234 respectively). Asians and Caucasians were more likely to complete their visits (80% and 74% respectively) compared to patients of Hispanic, African American and American Indian ethnicities where more cancel/no show visits were observed (40%, 29% and 29% respectively;p=0.002). The highest numbers of cancel/no show appointments were reported in March (48.8%) and April (45.6%) and were significantly different when compared to the other months (p=0.000). Conclusions : Intravitreal therapy is the standard care for a variety of retinal disorders and adherence to the proposed treatment regimen is important to maximize the visual acuity benefits and maintain the gains in the long term. In this cohort it was noted that vast majority of visits were canceled by the patients whereas underrepresented minorities were more likely not to complete their scheduled visits which could be partially explained by the fact that these groups are also disproportionately affected by COVID-19.