ScholarWorks@UMassAmherst

Recent Submissions

  • Publication
    Women at the Center
    (Center for International Education, UMass Amherst, 1979-11) Multiple Authors
    This document was published in 1979 at a time of increasing interest in the role of Women in Development (known at the time as WID.) Collectively, the women decided to document their interests and their commitment to participating in various ways as women in development. The document contains short bio-sketches of the interests and careers of more than 50 women who were either current students at CIE or who graduated earlier. They represent countries from all over the world – as indicated by the almost 25 different languages spoken by the women. Many of these women went on to leadership positions in education in their countries.
  • Publication
    Generic Indeterminacy of Steady-State Competitive Equilibria in Walras-von Neumann Production Economies
    (2025-04) Yoshihara, Naoki
    This paper studies the structure of the set of steady state equilibria defined in quite generalized von Neumann economic models. First, it is shown that in any von Neumann production economy, there exists an admissible domain of non-negative interest rates such that for every interest rate within the domain, there exists an associated steady state equilibrium. Second, for almost all interest rates within the domain, the associated steady state equilibrium is indeterminate. Thus, in summary, for any von Neumann production economy, there is a dense subset of the admissible domain over which the set of steady state equilibria consists of a finite number of one-dimensional continuums of those equilibria. This property is observed regardless of whether the underlying economy is regular or not, which contrasts sharply with the finite and discrete properties of the other types of Walrasian equilibria in both static and intertemporal regular economies. These main results suggest, as a new, future research agenda, the need to study an appropriate equilibrium selection mechanism that should be applied prior to market competition.
  • Publication
    Exploitation: theory and empirics
    (2025-04) Girardi, Daniele; Grau, Nicolas; Veneziani, Roberto; Yoshihara, Naoki
    This paper provides a novel axiomatic analysis of exploitation as the unequal exchange of labour, derives an empirical exploitation index at the individual level, and estimates its distribution in the US in 1975-2022. We show that, among possible definitions of exploitation, only one satisfies a small set of formally weak and normatively salient axioms. From this definition, we derive an individual-level exploitation intensity index which provides a new measure of well-being and inequality, complementary to existing ones and able to jointly take into account the distributions of income and work time. In US data, exploitation intensity provides additional information compared with standard income inequality measures and predicts important well-being and political outcomes. Inequality in exploitation increased more than income inequality since 1975.
  • Publication
    Environmental justice beyond race: Skin tone and exposure to air pollution
    (2025) Cardenas, Juan-Camilo; Gomez, Sandra Aguilar; Diaz, Ricardo Salas
    Recent research, focused mostly on the United States and Western Europe, shows that marginalized communities often face greater environmental degradation. However, the ethnoracial categories used in these studies may not fully capture environmental inequality in the Global South. Moving beyond conventional ethnoracial variables, this study presents findings exploring the link between skin tone and fine particulate matter (PM2.5) exposure in Colombia. By matching household geolocations from a large-scale longitudinal survey with satellite-based PM2.5 estimates, we find that skin tone predicts both initial pollution exposure levels and their changes over time. Although average exposure levels remained stable during our study period, the environmental justice (EJ) landscape in Colombia contemporaneously underwent a complete transformation. In 2010, lighter-skinned individuals faced higher PM2.5 exposure, but darker-skinned individuals experienced steeper increases in the following years. By 2016, the EJ gap had reversed, with people with the darkest skin tones exposed to PM2.5 levels nearly one SD higher than those faced by people with the lightest skin tones. These patterns remain robust when controlling for a comprehensive set of theoretically relevant covariates, including ethnoracial self-identification and income. Disproportionate exposure to pollution from fires partially explains the observed disparities. Decomposition analysis shows that this variable, local collective action, and economic marginalization account for a sizeable share of the EJ gap. However, one-third of the gap remains unexplained by observable characteristics. With climate change intensifying fire incidence, the disproportionate disease burdens that vulnerable groups face might deepen unless policy measures are taken to reverse this trend.
  • Publication
    Dynamics of a von Willebrand Factor A1 Autoinhibitory Module with O-Linked Glycans and Its Roles in Regulation of GPIbα Binding
    (2025) Zhang, Xiaohui (Frank); Cao, Yiwei; Im, Wonpil
    The von Willebrand factor (VWF), a multimeric plasma glycoprotein, binds to the platelet glycoprotein (GPIb alpha) to initiate the process of primary hemostasis as a response to blood flow alteration in the site of vascular injury. The GPIb alpha binding site located on the A1 domain of VWF is exposed during the activation of the VWF multimer when it changes from a coiled form to a thread-like, extended form. Though experimental studies have demonstrated that the autoinhibitory module (AIM) connected to the N-/C-termini of the A1 domain is a regulator of VWF activity, the molecular mechanism underlying the regulation of A1-GPIb alpha binding remains unclear. We modeled the structures of the A1 domain having full-length N-terminal AIM (NAIM) and C-terminal AIM (CAIM) with different types of O-linked glycans. The conventional and steered molecular dynamics simulations were conducted to investigate the dynamics of the AIM and O-glycans under different conditions and elucidate how they affect the binding of GPIb alpha. Our results indicate that the NAIM alone with no glycan is sufficient to shield the GPIb alpha binding site under static conditions. However, when the AIM is unfolded with external forces applied, the O-glycans on both NAIM and CAIM increase the shielding of the binding site. These findings suggest a potential mechanism by which the AIM and O-glycans regulate the interaction of the VWF A1 domain and GPIb alpha.