The Earned Income Tax Credit and the Labor Supply of Married Couples

Over 18 million taxpayers are projected to receive the Earned Income Tax Credit (EITC) in tax year 1997, at a total cost to the federal government of about 25 billion dollars. The EITC is refundable, so any amount of the credit exceeding the family’s tax liability is returned in the form of a cash refund. Advocates of the credit argue that this redistribution occurs with much less distortion to labor supply than that caused by other elements of the welfare system. This popular view that the credit “encourages work effort” is unlikely to hold among married couples. Theory suggests that primary earners (typically men) would increase labor force participation, but secondary earners would reduce their labor supply in response to an EITC. We study the labor supply response of married couples to several EITC expansions between 1984 and 1996. Although our primary interest is the response to changes in the budget set induced by the EITC, our estimation strategy takes account of budget set changes caused by federal tax policy, and by cross-sectional variation in wages, income, and family size. We use both quasi-experimental and reduced-form labor supply models to estimate the impact of EITC-induced tax changes. The results suggest that EITC expansions between 1984 and 1996 increased married men’s labor force participation only slightly but reduced married women’s labor force participation by over a full percentage point. Overall, the evidence suggests that family labor supply and pre-tax family earnings fell among married couples. Our results imply that the EITC is effectively subsidizing married mothers to stay at home, and therefore have implications for the design of the program.

Circular Economy Strategies For Reducing Embodied Carbon In US Commercial Building Stocks: A System Dynamics Modeling Approach

Environmental concerns over embodied carbon - which is generated during the extraction, transportation, manufacturing, construction, and disposal of building materials - have been increasing as the industry shifts to renewable energy and grid decarbonization efforts prevail. Commercial buildings, a rapidly growing sector and a major source of embodied carbon, can contribute immensely to the national climate goals by transitioning into a circular economy (CE). Nevertheless, embodied carbon research is rather dispersed, with sparse data on the actual impact of different CE strategies and how they scale on nationwide commercial building stocks. To address this research need, the goal of this paper is to provide policymakers with a conceptual model that depicts the potential of CE strategy portfolios on embodied carbon reduction of commercial building stocks. Using US commercial buildings data from the Energy Information Administration, the authors (1) developed a systems dynamics model to conceptualize and serve as a baseline for calculating existing embodied emissions; and (2) evaluated the influence of various policy packages in terms of their overall emissions reduction potential over a planning horizon between the years 2022 and 2050. Findings of the study highlight the effectiveness of early design and construction CE interventions as compared to end-of-life strategies such as recycling, as well as traditional and business-as-usual approaches. Ultimately, results of the developed model can aid decision-makers to create multiple what-if scenarios for their policies, in addition to capitalizing on the most effective strategies for narrowing material loops and curbing embodied carbon emissions

Data-Driven Analysis Of Progressive Design Build In Water And Wastewater Infrastructure Projects

The United States has invested heavily in water and wastewater infrastructure projects to address growing demand and aging systems. To ensure the effective delivery of these projects, agencies are shifting toward alternative delivery methods such as progressive design build (PDB), which has demonstrated accelerated schedule and enhanced cost performance across the literature as well as multiple projects compared to traditional DB. This has raised a need for evaluating PDB\u27s state of adoption and performance in the water and wastewater sector. To this end, the authors: (1) conducted descriptive and statistical analyses of the 21 PDB water and wastewater projects available on the Design-Build Institute of America database evaluating their characteristics and performance metrics; (2) investigated the frequency of materialized risks impacting schedule and cost in these projects; and finally (3) identified the key adoption drivers and challenges for PDB in the water and wastewater sector by triangulating findings from the studied narratives with a literature and practice review. Results revealed that 71% and 57% of the investigated projects were completed on or before the contracted schedules and costs, respectively. From the studied project narratives, owner-led changes and COVID-19 impacts were the most frequently encountered risks. Also, it was shown that project planning and risk management drivers were the most influential causes for PDB adoption, whereas legal and contractual restrictions as well as the owner\u27s mindset and culture-related concerns were the most pressing challenges. This study contributes to the body of knowledge by delivering managerial insights through an aggregated snapshot of PDB implementation in the water and wastewater sector. Ultimately, the provided managerial insights can assist stakeholders in making better-informed decisions by weighing the advantages and challenges of PDB identified in this research against more traditional delivery approaches

Risk–Reward Share Allocation Under Different Integrated Project Delivery Relational Structures: A Monte-Carlo Simulation And Cooperative Game Theoretic Solutions Approach

Sharing of risks and rewards is considered to be one of the key benefits and principles of integrated project delivery (IPD). Despite its importance, risk–reward strategies are not implemented widely in IPD construction projects due to the lack of a well-defined basis for establishing adequate allocation plans. This paper fills this knowledge gap. This research followed a multistep methodology. First, the authors calculated the risk control valuations of all potential combinations of coalitions for IPD stakeholders. This was performed using interrelated steps of risk identification and quantification, risk assignment based on associated contractual analysis, establishment of a coordination network, and Monte Carlo simulation. Second, the authors adopted cooperative game theoretic solutions—including Shapely, Owen, and Myerson partition-graph restricted game values—to allocate risk–reward shares for three IPD relational structures. Third, for each IPD relational structure, the authors evaluated the stability and associated negotiation power of coalitions for the IPD stakeholders using the propensity-to-disrupt ratio. Ultimately, the outcomes of this study show that having a multiparty agreement, in which all stakeholders—the owner, designer, contractor, and subcontractor—have open communication channels, creates the most balanced coalition. In this case, all stakeholders have equal willingness to cooperate in the project. Furthermore, as the engagement of the subcontractor in the IPD coalition decreases, the liability and contribution of the contractor increase in terms of project risk control. The latter emphasizes the importance of the technical capabilities of the contractor in the case of restricted subcontractor\u27s engagement in the project. This research contributes to the body of knowledge by offering a basis for negotiation among various IPD stakeholders in terms of the degree of the subcontractor\u27s engagement on the one hand and the proportionate share of each stakeholder on the other hand

Development of chitosan-glucose and chitosan-citric complexes edible coating to improve tomatoes post-harvest quality

 The effect of different shrimp chitosan molecular weights as well as shrimp chitosan complexes (chitosan-glucose and chitosan-citric) on the quality characteristics of the stored (at 7°C±2°C and 90% RH) tomato fruits (Lycopersicum esculentum) was investigated.  Coating tomatoes with high molecular weight chitosan (H.M.C.G) significantly improved firmness and weight loss.  The lowest weight loss was found in high molecular weight chitosan-glucose (H.M.C.G) treatment followed by the fruits coated with high molecular weight chitosan (HMC) and then uncoated tomato fruits.  Both molecular weights was clear on retarding the total acidity loss especially for stored tomato fruit coated with low molecular weight chitosan, while control tomatoes exhibited a larger reduction (p ≤ 0.05) in total acidity over storage.  Meanwhile, the increasing of cold storage time significantly (p ≥ 0.05) increased the pH in all uncoated and coated tomatoes.  Generally, no significant (P > 0.05) difference was observed in pH, titratable acidity and total soluble solids (T.S.S.) as well as sensory attributes among the tomato fruits coated with chitosan, chitosan citric and chitosan glucose.  Meanwhile, the fruits coated with low molecular weight chitosan had a higher (p ≥ 0.05) T.S.S. compared with that coated by the high molecular weight chitosan.   Keywords: chitosan, edible coating, tomatoes, firmness and weight loss

The frequency of IgM-anti HAV in the sera of patients with hepatitis in Iraq

Three hundred and fifty five patients with hepatitis were investigated in this study all cases gave negative result with HBs Ag , IgM-anti HCV , IgM-anti HEV, IgM-anti HDV and anti-HIV tests . The frequency of IgM-anti HAV was 113 and the percentage was 32 % in all ages but when these patients divided into five groups dependent on ages. The highest percentage of IgM-anti HAV was (45%) in age 41 year