7,806 research outputs found
Why work? : the contribution of value perceptions and efficacy expectations to organizational commitment
The dissertation describes a project aimed at an understanding of the way both (congruence between) organizational and individual values and efficacy expectations contribute to organizational commitment
Multiple configuration shell-core structured robotic manipulator with interchangeable mechatronic joints : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Engineering in Mechatronics at Massey University, Turitea Campus, Palmerston North, New Zealand
With the increase of robotic technology utilised throughout industry, the need for skilled
labour in this area has increased also. As a result, education dealing with robotics has
grown at both the high-school and tertiary educational level. Despite the range of
pedagogical robots currently on the market, there seems to be a low variety of these
systems specifically related to the types of robotic manipulator arms popular for industrial
applications. Furthermore, a fixed-arm system is limited to only serve as an educational
supplement for that specific configuration and therefore cannot demonstrate more than
one of the numerous industrial-type robotic arms.
The Shell-Core structured robotic manipulator concept has been proposed to improve the
quality and variety of available pedagogical robotic arm systems on the market. This is
achieved by the reconfigurable nature of the concept, which incorporates shell and core
structural units to make the construction of at least 5 mainstream industrial arms
possible. The platform will be suitable, but not limited to use within the educational
robotics industry at high-school and higher educational levels and may appeal to
hobbyists.
Later dubbed SMILE (Smart Manipulator with Interchangeable Links and Effectors), the
system utilises core units to provide either rotational or linear actuation in a single plane.
A variety of shell units are then implemented as the body of the robotic arm, serving as
appropriate offsets to achieve the required configuration. A prototype consisting of a
limited number of âbuilding blocksâ was developed for proof-of-concept, found capable of
achieving several of the proposed configurations.
The outcome of this research is encouraging, with a Massey patent search confirming the
unique features of the proposed concept. The prototype system is an economic, easy to
implement, plug and play, and multiple-configuration robotic manipulator, suitable for
various applications
Disability insurance and unemployment insurance as substitute pathways
In this paper, we estimate the degree of substitution between enrolment into Disability Insurance (DI) and Unemployment Insurance (UI) in the Netherlands. Starting in the 1990s many policy measures aimed at reducing DI enrolment, and increase labour force participation. We quantify whether these policy measures have led to a reduction in hidden unemployment in DI. A side effect of the reforms may be increased pressure on UI. Therefore, we simultaneously estimate reverse substitution, that is, hidden disability in UI. To this end, we employ a sample of firms in the Dutch AVO database from the period 1993-2002. Using instrumental variables in a bivariate Tobit specification, we identify the hidden components in both respective schemes. The estimation results indicate that about 3% of all dismissals took place through DI, which implies that about one quarter of the DI enrolments observed in our sample in fact consists of hidden unemployment. We find no evidence for reverse substitution of disabled persons ending up in UI.
The decentralization of Social Assistance and the rise of Disability Insurance enrolment
In this paper, we assess spillover effects of Social Assistance (SA) decentralization in the Netherlands, in particular towards (a centrally administered) Disability Insurance scheme (DI). DI enrolment has increased strongly since the decentralization of SA. Many economists and policymakers believe that fiscal decentralization, the decentralization of government expenditures to local governments, enhances public sector efficiency. Vertical externalities â i.e. spillovers between local and central government â may however undo part of this advantage. In this paper, we assess spillover effects of Social Assistance (SA) decentralization in the Netherlands, in particular towards (a centrally administered) Disability Insurance scheme (DI). DI enrolment strongly increased since the decentralization of SA. We find that the sensitivity of local DI enrolment with respect to the stock of local SA recipients has increased over time, given that we control for both observed and unobserved disability risk factors. IV estimates show that, since the decentralization of SA, at least one third of DI inflow was diverted from SA.
A Flexible Test for Present Bias and Time Preferences Using Land-Lease Contracts
When agents have present bias, they discount more between now and the next period than between period t (> 1) and t + 1. How fast the future discount rate (evaluated today) decays is an empirical question. We show that the discount function can be non-parametrically identified with contracts that specify payments that take place at various points in time in the future and which are traded and priced in a competitive market. We use a unique land lease-contract data set for Amsterdam, which has the above properties, to test for present bias in a flexible way. We find no evidence for present bias in this market. Even though we allow for a general-hyperbolic specification (which has exponential discounting as a special case), our estimates converge to an exponential discount function with a corresponding discount rate (in our baseline specification) of 8 %.present bias, hyperbolic discounting, discount rate, hedonic estimation
Hidden unemployment in disability insurance in the Netherlands; an empirical analysis based on employer data
In this paper, we construct and estimate a (semi-) structural model, so as to uncover the fraction of hidden unemployment in the Disability Insurance (DI) enrolment rate. For this purpose, we use longitudinal administrative data of Dutch employers for 1994-2003. We find the (average) fraction of hidden unemployment in DI enrolment to amount to about 11%. This corresponds to 2.6% of the âtrueâ unemployment insurance (UI) enrolment rate of employers. Over the years, we observe a strong decrease in this fraction, from 5.4% in 1995, to 0.7% in 2003. In addition, our estimates suggest that most of correlation that is observed between the UI and DI enrolment rates can be explained by substitution effects, and not by âtrueâ correlation between the schemes that is exogenous to the firm. In the model, the fraction of hidden unemployment in the DI scheme is (over-)identified from various restrictions imposed by the data. First, identification follows from exclusion restrictions obtained from the coefficient estimates of variables that are assumed to influence the UI enrolment rate only. For this purpose, we use information on the wage distribution of workers employed at the firms in our sample, and sectoral growth rates. Second, identification of substitution effects follows from the observed correlation between both enrolment rates.
Nonseparable sample selection models with censored selection rules: an application to wage decompositions
We consider identification and estimation of nonseparable sample selection models with censored selection rules. We employ a control function approach and discuss different objects of interest based on (1) local effects conditional on the control function, and (2) global effects obtained from integration over ranges of values of the control function. We provide conditions under which these objects are appropriate for the total population. We also present results regarding the estimation of counterfactual distributions. We derive conditions for identification for these different objects and suggest strategies for estimation. We also provide the associated asymptotic theory. These strategies are illustrated in an empirical investigation of the determinants of female wages and wage growth in the United Kingdom.https://arxiv.org/abs/1801.08961First author draf
Are older workers overpaid? A literature review
It is widely believed that wage and productivity profiles of individual workers do not coincide at all ages. We give an overview of the theories which provide a rationale for this, and discuss the empirical literature. Human capital theories typically imply that wages rise with tenure, so that job reallocation at old age would imply a wage cut. Incentive theories typically imply that wages exceed productivity at the end of a worker's career. Bargaining power of unions may also lead to 'overpayment' of older workers. Some general conclusions regarding the wages of older workers are formulated on the basis of the authors' reading of the empirical literature.
The impact of homeownership on unemployment in the Netherlands
We analyze the impact of homeownership on unemployment duration using a theoretical model of job search. Earlier studies suggest that this relationship should be positive because workers are less mobile when they own a home. Nevertheless, most of the empirical studies in Europe find an opposite relationship. In this paper, we investigate whether this is due to an omission in the original analysis or whether it is due to an endogeneity problem, i.e. those who can leave unemployment easily are more likely to be a homeowner. In our empirical analysis, we use additional information about the differences in unemployment benefits between homeowners and renters. We find that homeowners have higher hazard rates out of unemployment to a job in the local labour market. The impact is significant but not very large. Homeownership has a negative but insignificant impact on the hazard to leave unemployment to the non-local labour market. Finally, we find that homeowners would reduce their probability to receive a job offer from the local labour market when they become renters. The probability to receive a job offer from the non-local labour market would increase for short spells of unemployment when home owners become renters. However, this probability would be reduced for long spells of unemployment.
A Flexible Test for Present Bias and Time Preferences Using Land-Lease Contracts
When agents have present bias, they discount more between now and the next period than between period t (> 1) and t + 1. How fast the future discount rate (evaluated today) decays is an empirical question. We show that the discount function can be non-parametrically identified with contracts that specify payments that take place at various points in time in the future and which are traded and priced in a competitive market. We use a unique land lease-contract data set for Amsterdam, which has the above properties, to test for present bias in a flexible way. We find no evidence for present bias in this market. Even though we allow for a general-hyperbolic specification (which has exponential discounting as a special case), our estimates converge to an exponential discount function with a corresponding discount rate (in our baseline specification) of 8 %.present bias, hyperbolic discounting, discount rate, hedonic estimation
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