Piece-Rates, Principal-Agent, and Productivity Profiles: Parametric and Semi-Parametric Evidence

This paper exploits the natural link between observed wages and productivity that is inherent in piece-rate wage data to estimate worker productivity profiles. Piece-rate wages are functions of the parameters of the compensation system and worker effort. Identifying productivity from such data requires separating out these effects. This can be accomplished by explicitly modelling the principal-agent relationship between the worker and the firm and deriving optimal decision rules for worker effort. This approach is applied to historical payroll data collected from a British Columbia copper mine. The salient aspects of the mine's production process are incorporated into the model, namely, asymmetric information, team production and heterogeneous workers. Solving the model for equilibrium worker effort implies a censored wage distribution which is estimated both parametrically and semi-parametrically. Methods to control for unobserved heterogeneity among workers are also used. Productivity profiles are then constructed from the resulting parameter estimates. Results suggest that productivity profiles were increasing concave functions of worker tenure. Cette étude utilise le lien naturel qui existe entre les salaire observés et la productivité des travailleurs lorsque les travailleurs sont payés à la pièce afin d'estimer les profils de productivité des travailleurs. Quand les travailleurs sont payés à la pièce, les salaires observés sont une fonction des paramètres du système de compensation et du niveau d'effort des travailleurs. L'identification de la productivité des travailleurs nécessite la séparation de ces deux effets dans les données. Ceci peut être accompli en modélisant la relation principal-agent qui existe entre la firme et le travailleur tout en trouvant les règles de comportement optimal de l'effort du travailleur. Cette approche est appliquée à des données de salaires historiques, colligées à partir des archives d'une mine en Colombie-Britannique. Les aspects importants de la technologie de la mine sont incorporés dans le modèle, ie. l'asymétrie d'information qui existe entre la firme et les travailleurs, la production en équipe et les travailleurs hétérogènes. Le modèle est résolu pour le niveau d'effort du travailleur en équilibre. Celui-ci implique une distribution de salaires censorés qui est estimée de façon paramétrique et semi-paramétrique tout en contrôlant pour l'hétérogénéité inobservable des travailleurs. Les profils de productivité sont construits à partir des paramètres estimés. Les résultats suggèrent que les profils de productivité étaient des fonctions croissantes et concaves de l'ancienneté du travai, Modèle du principal-agent ; Productivité de travail; Système de prime; Modèle de régression censorée ; Estimations semi-paramétriques

2,4-D and Mycoleptodiscus terrestris for control of Eurasian Watermilfoil

Growth chamber studies were conducted to evaluate the impact of an indigenous fungal pathogen, Mycoleptodiscus terrestris (Gerd.) Ostazeski, and the herbicide 2,4-D applied alone and in combination with one another, on the growth of a nuisance submersed plant, Eurasian watermilfoil ( Myriophyllum spicatum L.)(PDF has 6 pages.

On the Relevance and Composition of Gifts within the Firm: Evidence from Field Experiments

We investigate the economic relevance and the composition of gifts within a firm where output is contractible. We develop a structural econometric model that identifies workers' optimal reaction to monetary gifts received from their employer. We estimate the model using data from two separate field experiments, both conducted within a tree-planting firm. We use the estimated structural parameters to generalize beyond the experiment, simulating how workers would react to different gifts on the part of the firm, within different labour-market settings. We find that gifts have a role to play within this firm, increasing in importance when the workers' outside alternatives deteriorate. Profit-maximizing gifts would increase profits within slack labour markets by up to 10% on average and by up to 17% for certain types of workers. These gifts represent significant increases in worker earnings; the average gift paid to workers attains 22% of average expected earnings in the absence of gifts. We find that gifts should be given by setting piece-rates above the market-clearing level rather than through fixed wages.gift giving, structural models, field experiments

Sorting, Incentives and Risk Preferences: Evidence from a Field Experiment

The, often observed, positive correlation between incentive intensity and risk has been explained in two ways: the presence of transaction costs as determinants of contracts and the sorting of risk-tolerant individuals into firms using high-intensity incentive contracts. The empirical importance of sorting is perhaps best evaluated by directly measuring the risk tolerance of workers who have selected into incentive contracts under risky environments. We use experiments, conducted within a real firm, to measure the risk preferences of a sample of workers who are paid incentive contracts and face substantial daily income risk. Our experimental results indicate the presence of sorting; Workers in our sample are risk-tolerant. Moreover, their level of tolerance is considerably higher than levels observed for samples of individuals representing broader populations. Interestingly, the high level of risk tolerance suggests that both sorting and transaction costs are important determinants of contract choices when workers have heterogeneous preferences.Risk aversion, sorting, incentive contracts, field experiments

Male-Female Productivity Differentials: the Role of Ability and Incentives

We consider the response to incentives as an explanation for productivity differences within a firm that paid its workers piece rates. We provide a framework within which observed productivity differences can be decomposed into two parts: one due to differences in ability and the other due to differences in the response to incentives. We apply this decomposition to male and female workers a tree-planting firm in the province of British Columbia, Canada. We provide evidence that individuals do react differently to incentives. However, while the women in our sample reacted slightly more to incentives than did the men, the average difference is not statistically significant. The productivity differential that men enjoyed arose because of differences in ability, strength in our application.Productivity, Gender, Compensation, Incentives

Male-Female Productivity Differentials: the Role of Ability and Incentives (revised)

We consider the response to incentives as an explanation for productivity differences within a firm that paid its workers piece rates. We provide a framework within which observed productivity differences can be decomposed into two parts: one due to differences in ability and the other due to differences in the response to incentives. We apply this decomposition to male and female workers from a tree-planting firm in the province of British Columbia, Canada. We provide evidence that individuals do react differently to incentives. However, while the women in our sample reacted slightly more to incentives than did the men, the average difference is not statistically significant. The productivity differential that men enjoyed arose because of differences in ability, strength in our application.Productivity, Gender, Compensation, Incentives

Work Sharing and Productivity : Evidence from a Natural Experiment

This paper is the first to examine empirically how work sharing influences workers' productivity, using a unique data set from a large Canadian firm. This firm has adopted a work sharing scheme for one year, which allows us to introduce a natural experiment approach of comparing workers' productivity before and after the implementation of work sharing. We find that work sharing has led to a significant decrease in labor productivity. Cet article examine empiriquement l'impact du partage du travail sur la productivité des travailleurs d'une grande firme canadienne. L'application de la semaine réduite de travail pendant un an au sein de cette entreprise nous permet de comparer analytiquement la productivité des employés avant et après l'adoption de ce programme. Nos résultats révèlent que l'expérimentation de la semaine réduite de travail provoque une baisse significative de la productivité des travailleurs.Productivity, Work Sharing, Work Organisation Methods, Productivité, partage du travail, modes d'organisation du travail

Labour Supply, Work Effort and Contract Choice: Theory and Evidence on Physicians

We develop and estimate a generalized labour supply model that incorporates work effort into the standard consumption-leisure trade-off. We allow workers a choice between two contracts: a piece rate contract, wherein he is paid per unit of service provided, and a mixed contract, wherein he receives an hourly wage and a reduced piece rate. This setting gives rise to a non-convex budget set and an efficient budget constraint (the upper envelope of contract-specific budget sets). We apply our model to data collected on specialist physicians working in the Province of Quebec (Canada). Our data set contains information on each physician's labour supply and their work effort (clinical services provided per hour worked). It also covers a period of policy reform under which physicians could choose between two compensation systems: the traditional fee-for-service, under which physicians receive a fee for each service provided, and mixed remuneration, under which physicians receive a per diem as well as a reduced fee-for-service. We estimate the model using a discrete choice approach. We use our estimates to simulate elasticities and the effects of ex ante reforms on physician contracts. Our results show that physician services and effort are much more sensitive to contractual changes than is their time spent at work. Our results also suggest that a mandatory reform, forcing all physicians to adopt the mixed remuneration system, would have had substantially larger effects on physician behaviour than those observed under the voluntary reform.labour supply, effort, contracts, practice patterns of physicians, discrete choice econometric models, mixed logit

The Minnesota Multiphasic Personality Inventory-2 and Low Back Pain Surgery Outcome

Chronic back pain is a serious problem in the U.S. for which about 10% of back pain sufferers will undergo elective surgery. Unfortunately, back surgery is not successful in alleviating back pain in a substantial number of surgery patients. Various psychological and psychosocial variables have a demonstrated relationship to back surgery outcome. The most widely used personality test used to predict back surgery outcome is the Minnesota Multiphasic Personality Inventory (MMPJ). Past research has shown that elevations on three MMPI clinical scales (Hs, D, and Hy) are positively correlated with poor back surgery outcome. The current prospective study shows a similar pattern using the MMPI-2 to predict surgery outcome for 60 low back pain patients. It appears that past MMPI research in this area is applicable to the use of MMPI-2. These results also suggest that when MMPI-2 variables are combined with demographic and surgical variables, patients more likely to experience poor surgical outcome can be identified. There is evidence that elevations of the conversion V profile of the MMPI-2 may prospectively differentiate between successful and nonsuccessful surgery outcomes

Feeding and Management of Sheep

Sheep raising in Iowa is normally a profitable enterprise. All parts of the state are well adapted to it. Sheep production is not a major enterprise on most Iowa farms and probably should not be. Observation and experience indicate that the best plan is to keep a farm flock as a part of a diversified livestock production program