Stochastic frontier, Panel data, Technical efficiency, Size, Organisational factors, C23, J21, J29, L60, L26,

The primary focus of this paper is on efficiency wages and their testable implications. In particular the nature of the relationship between efficiency wages, productivity and the make up of the labour force is analysed, modelled and subjected to an empirical test. This theory is consistent with the views of many managers and personal administrators, who tend to ascribe primary importance in wage setting to indirect control of the firm's workforce. Here we test a labour augmenting production function where effort depends not only on wages but also on the proportion of temporary workers.

This paper provides an explanation for the existence of gender discrimination in the labour market focusing on the intergenerational transmission of preferences related to the attitude of women towards jobs and family. Changes in women's preferences over generations depend on the socialization efforts of their parents which in turn are influenced by both the firm's expected recruitment policy and the expected utility from household care. We obtain two types of steady state equilibria: the discriminatory equilibrium, in which women are segregated to low-paid jobs, and the non-discriminatory equilibrium, in which women are hired in highly-paid jobs. The conditions of convergence to each equilibrium are analysed.

ImportanceGreater than 20% of cases and 0.4% of deaths from COVID-19 occur in children. Following demonstration of the safety and efficacy of the adjuvanted, recombinant spike protein vaccine NVX-CoV2373 in adults, the PREVENT-19 trial immediately expanded to adolescents.ObjectiveTo evaluate the safety, immunogenicity, and efficacy of NVX-CoV2373 in adolescents.Design, Setting, and ParticipantsThe NVX-CoV2373 vaccine was evaluated in adolescents aged 12 to 17 years in an expansion of PREVENT-19, a phase 3, randomized, observer-blinded, placebo-controlled multicenter clinical trial in the US. Participants were enrolled from April 26 to June 5, 2021, and the study is ongoing. A blinded crossover was implemented after 2 months of safety follow-up to offer active vaccine to all participants. Key exclusion criteria included known previous laboratory-confirmed SARS-CoV-2 infection or known immunosuppression. Of 2304 participants assessed for eligibility, 57 were excluded and 2247 were randomized.InterventionsParticipants were randomized 2:1 to 2 intramuscular injections of NVX-CoV2373 or placebo, 21 days apart.Main Outcomes and MeasuresSerologic noninferiority of neutralizing antibody responses compared with those in young adults (aged 18-25 years) in PREVENT-19, protective efficacy against laboratory-confirmed COVID-19, and assessment of reactogenicity and safety.ResultsAmong 2232 participants (1487 NVX-CoV2373 and 745 placebo recipients), the mean (SD) age was 13.8 (1.4) years, 1172 (52.5%) were male, 1660 (74.4%) were White individuals, and 359 (16.1%) had had a previous SARS-CoV-2 infection at baseline. After vaccination, the ratio of neutralizing antibody geometric mean titers in adolescents compared with those in young adults was 1.5 (95% CI, 1.3-1.7). Twenty mild COVID-19 cases occurred after a median of 64 (IQR, 57-69) days of follow-up, including 6 among NVX-CoV2373 recipients (incidence, 2.90 [95% CI, 1.31-6.46] cases per 100 person-years) and 14 among placebo recipients (incidence, 14.20 [95% CI, 8.42-23.93] cases per 100 person-years), yielding a vaccine efficacy of 79.5% (95% CI, 46.8%-92.1%). Vaccine efficacy for the Delta variant (the only viral variant identified by sequencing [n = 11]) was 82.0% (95% CI, 32.4%-95.2%). Reactogenicity was largely mild to moderate and transient, with a trend toward greater frequency after the second dose of NVX-CoV2373. Serious adverse events were rare and balanced between treatments. No adverse events led to study discontinuation.Conclusions and RelevanceThe findings of this randomized clinical trial indicate that NVX-CoV2373 is safe, immunogenic, and efficacious in preventing COVID-19, including the predominant Delta variant, in adolescents.Trial RegistrationClinicalTrials.gov Identifier: NCT04611802