18,117 research outputs found
Evaluating the labour market impact of Working Families' Tax Credit using difference-in-differences
A difference-in-differences methodology cannot identify the labour market impact of WFTC alone because other taxes and benefits changed at the same time as its introduction. However, a comparison of the change in employment rates for parents against adults without children should underestimate any positive labour supply impact of WFTC for lone parents. Using two different household surveys, we find WFTC and associated reforms increased lone parents' employment by around 3.6 percentage points (ppt). For couples with children, we find that WFTC and associated reforms had no significant effect on mothers' employment, and was associated with a -0.5ppt change in fathers' employment, with the reforms encouraging households to have one earner rather than two. Overall, these changes correspond to between 25,000 and 59,000 extra workers depending upon the data source used. Robustness analysis of our identifying assumptions is generally favourable to our conclusions for lone parents
Job changes, hours changes, and the path of labour supply adjustment
This paper uses the first twelve waves of the British Household Panel Survey covering the period
1991-2002 to investigate single women’s labour supply changes in response to three tax and benefit
policy reforms that occurred in the 1990s. We find evidence of small labour supply effects for two
of such reforms. A third reform in 1999 instead led to a significant increase in single mothers’ hours
of work. This increase was primarily driven by women who changed job, suggesting that labour
supply adjustments within a job are harder than across jobs. The presence of hours inflexibility
within jobs and labour supply adjustments through job mobility are strongly confirmed when we
look at hours changes by stated labour supply preferences. Finally, we find little overall effect on
wages
Pressure and heat flux results from the space shuttle/external fuel tank interaction test at Mach numbers 16 and 19
Heat transfer rates and pressures were measured on a 0.0175-scale model of the space shuttle external tank (ET), model MCR0200. Tests were conducted with the ET model separately and while mated with a 0.0175-scale model of the orbiter, model 21-OT (Grumman). The tests were conducted in the AEDC-VKF Hypervelocity Wind Tunnel (F) at Mach numbers 16 and 19. The primary data consisted of the interaction heating rates experienced by the ET while mated with the orbiter in the flight configuration. Data were taken for a range of Reynolds numbers from 50,000 to 65,000 under laminar flow conditions
Minimum energy, liquid hydrogen supersonic cruise vehicle study
The potential was examined of hydrogen-fueled supersonic vehicles designed for cruise at Mach 2.7 and at Mach 2.2. The aerodynamic, weight, and propulsion characteristics of a previously established design of a LH2 fueled, Mach 2.7 supersonic cruise vehicle (SCV) were critically reviewed and updated. The design of a Mach 2.2 SCV was established on a corresponding basis. These baseline designs were then studied to determine the potential of minimizing energy expenditure in performing their design mission, and to explore the effect of fuel price and noise restriction on their design and operating performance. The baseline designs of LH2 fueled aircraft were than compared with equivalent designs of jet A (conventional hydrocarbon) fueled SCV's. Use of liquid hydrogen for fuel for the subject aircraft provides significant advantages in performance, cost, noise, pollution, sonic boom, and energy utilization
Study of LH2 fueled subsonic passenger transport aircraft
The potential of using liquid hydrogen as fuel in subsonic transport aircraft was investigated to explore an expanded matrix of passenger aircraft sizes. Aircraft capable of carrying 130 passengers 2,780 km (1500 n.mi.); 200 passengers 5,560 km (3000 n.mi.); and 400 passengers on a 9,265 km (5000 n.mi.) radius mission, were designed parametrically. Both liquid hydrogen and conventionally fueled versions were generated for each payload/range in order that comparisons could be made. Aircraft in each mission category were compared on the basis of weight, size, cost, energy utilization, and noise
Micro-simulating child poverty in 2010 and 2020
The 2008 Pre-Budget Report (PBR) said that 'the Government will take stock of progress towards its 2010 and 2020 child poverty target in the [2009] Budget'. As background to that exercise, this paper updates our previous analysis of the prospects for child poverty in the UK in 2010-11 and 2020-21
Rehabilitation planning for small tanks in cascades: a methodology based on rapid assessment
Irrigation systems / Rehabilitation / Tank irrigation / Small-scale systems / Reservoirs / Conflict / Farmer participation / River Basin development / Water resources development / Arid zones / Sri Lanka
Water distribution rules and water distribution performance: a case study in the Tambraparani Irrigation System
Irrigation management / Irrigation systems / Performance / Irrigation operation / Irrigation scheduling / Water distribution / Water allocation / Water delivery / Water users' associations / Legislation / Large-scale systems / Bananas / Case studies / India / Tamil Nadu / Tambraparani Irrigation System
The political dimension of seasonal allocations: Developing a seasonal allocation strategy in a water-short system in Sri Lanka
Water allocation, Irrigation programs, Reservoirs, Participatory management, Farmer participation, Water rights, Irrigated farming, Rice, Water shortage, Farmers' attitudes, Farmer-agency interactions, Sri Lanka
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