98 research outputs found
Welfare through regulatory means: eviction and repossession policies in Singapore*
The study and provision of welfare have long been synonymous with direct social spending. The provision of welfare through regulatory means poses a complementary perspective to the study of social policy. In this context, this paper focuses on policies aimed at preventing mortgage borrowers’ eviction and repossession in Singapore, a world leader in state-led owner occupancy but a welfare laggard in terms of social spending. The findings show a disparity between a high rate of arrears on housing credit, and a low level of eviction and repossession. We test several explanations for this disparity, and argue that it is the result of policy aiming to minimize eviction and repossessions. This policy is driven by institutional interdependencies within the state, which have tied citizens’ housing credit to other aspects of their individual welfare savings. The findings shed light on the central role of regulation in welfare
Universal basic income: inspecting the mechanisms
We consider the aggregate and distributional impact of Universal Basic Income (UBI). We develop a model to study a wide range of UBI programs and financing schemes and to highlight the key mechanisms behind their impact. The most crucial channel is the rise in distortionary taxation (required to fund UBI) on labor force participation. Second in importance is the decline in self-insurance due to the insurance UBI provides, resulting in lower aggregate capital. Third, UBI creates a positive income effect lowering labor force participation. Alternative tax-transfer schemes mitigate the impact on labor force participation and the cost of UBI
Fully Polynomial Time Approximation Schemes for Stochastic Dynamic Programs
We present a framework for obtaining fully polynomial time approximation schemes (FPTASs) for stochastic univariate dynamic programs with either convex or monotone single-period cost functions. This framework is developed through the establishment of two sets of computational rules, namely, the calculus of K-approximation functions and the calculus of K-approximation sets. Using our framework, we provide the first FPTASs for several NP-hard problems in various fields of research such as knapsack models, logistics, operations management, economics, and mathematical finance. Extensions of our framework via the use of the newly established computational rules are also discussed
Approximating the Nonlinear Newsvendor and Single-Item Stochastic Lot-Sizing Problems When Data Is Given by an Oracle
The single-item stochastic lot-sizing problem is to find an inventory replenishment policy in the presence of discrete stochastic demands under periodic review and finite time horizon. A closely related problem is the single-period newsvendor model. It is well known that the newsvendor problem admits a closed formula for the optimal order quantity whenever the revenue and salvage values are linear increasing functions and the procurement (ordering) cost is fixed plus linear. The optimal policy for the single-item lot-sizing model is also well known under similar assumptions.
In this paper we show that the classical (single-period) newsvendor model with fixed plus linear ordering cost cannot be approximated to any degree of accuracy when either the demand distribution or the cost functions are given by an oracle. We provide a fully polynomial time approximation scheme for the nonlinear single-item stochastic lot-sizing problem, when demand distribution is given by an oracle, procurement costs are provided as nondecreasing oracles, holding/backlogging/disposal costs are linear, and lead time is positive. Similar results exist for the nonlinear newsvendor problem. These approximation schemes are designed by extending the technique of K-approximation sets and functions.National Science Foundation (U.S.) (Contract CMMI-0758069)United States. Office of Naval Research (Grant N000141110056
Obstetric anesthesia services in Israel snapshot (OASIS) study: A 72 hour cross-sectional observational study of workforce supply and demand
BACKGROUND: We planned an observational study to assess obstetric anesthesia services nationwide. We aimed to assess the effect of the anesthesia workload/workforce ratio on quality and safety outcomes of obstetric anesthesia care.
METHODS: Observers prospectively collected data from labor units over 72 h (Wednesday, Thursday and Friday). Independent variables were workload (WL) and workforce (WF). WL was assessed by the Obstetric Anesthesia Activity Index (OAAI), which is the estimated time in a 24-h period spent on epidurals and all cesarean deliveries. Workforce (WF) was assessed by the number of anesthesiologists dedicated to the labor ward per week. Dependent variables were the time until anesthesiologist arrival for epidural (quality measure) and the occurrence of general anesthesia for urgent Cesarean section, CS, (safety measure). This census included vaginal deliveries and unscheduled (but not elective) CS.
RESULTS: Data on 575 deliveries are from 12 maternity units only, primarily because a major hospital chain chose not to participate; eight other hospitals lacked institutional review board approval. The epidural response rate was 94.4%; 321 of 340 parturients who requested epidural analgesia (EA) received it. Of the 19 women who requested EA but gave birth without it, 14 (77%) were due to late arrival of the anesthesiologist. Median waiting times for anesthesiologist arrival ranged from 5 to 28 min. The OAAI varied from 4.6 to 25.1 and WF ranged from 0 to 2 per shift. Request rates for EA in hospitals serving predominantly orthodox Jewish communities and in peripheral hospitals were similar to those of the entire sample. More than a fifth (13/62; 21%) of the unscheduled CS received general anesthesia, and of these almost a quarter (3/13; 23%) were attributed to delayed anesthesiologist arrival.
CONCLUSIONS: Inadequate WF allocations may impair quality and safety outcomes in obstetric anesthesia services. OAAI is a better predictor of WL than delivery numbers alone, especially concerning WF shortage. To assess the quality and safety of anesthetic services to labor units nationally, observational data on workforce, workload, and clinical outcomes should be collected prospectively in all labor units in Israel
Relationship between Hexokinase and the Aquaporin PIP1 in the Regulation of Photosynthesis and Plant Growth
Increased expression of the aquaporin NtAQP1, which is known to function as a plasmalemma channel for CO2 and water, increases the rate of both photosynthesis and transpiration. In contrast, increased expression of Arabidopsis hexokinase1 (AtHXK1), a dual-function enzyme that mediates sugar sensing, decreases the expression of photosynthetic genes and the rate of transpiration and inhibits growth. Here, we show that AtHXK1 also decreases root and stem hydraulic conductivity and leaf mesophyll CO2 conductance (gm). Due to their opposite effects on plant development and physiology, we examined the relationship between NtAQP1 and AtHXK1 at the whole-plant level using transgenic tomato plants expressing both genes simultaneously. NtAQP1 significantly improved growth and increased the transpiration rates of AtHXK1-expressing plants. Reciprocal grafting experiments indicated that this complementation occurs when both genes are expressed simultaneously in the shoot. Yet, NtAQP1 had only a marginal effect on the hydraulic conductivity of the double-transgenic plants, suggesting that the complementary effect of NtAQP1 is unrelated to shoot water transport. Rather, NtAQP1 significantly increased leaf mesophyll CO2 conductance and enhanced the rate of photosynthesis, suggesting that NtAQP1 facilitated the growth of the double-transgenic plants by enhancing mesophyll conductance of CO2
Fully polynomial-time approximation schemes for time–cost tradeoff problems in series–parallel project networks
- …