A theory of salesforce compensation plans is presented where the sales of a product depend not only on the salesperson's effort but also on the uncertainty in the selling environment. The firm chooses a compensation plan to maximize its profit taking into account the salesperson's likely effort levels under alternative compensation plans and his or her alternative job opportunities. The salesperson (agent) chooses an effort level considering both the disutility from effort and the expected utility from earnings under the compensation plan. The Agency Theory framework provides an explanation for the differences across firms in the types of compensation plans used such as straight salary, straight commissions, or a combination of salary and commissions. It is shown that the optimal compensation plan is a convex (concave) increasing function of sales if the risk tolerance of the salesperson increases “rapidly” (stays constant) with income. We identify several structural parameters that affect the compensation plan and show that the implication of changes in some of these parameters is consistent with those mentioned in the sales management literature. For example, we show that the proportion of salary to total compensation would increase with an increase in one or more of the following parameters: (i) uncertainty, (ii) marginal cost of production, and (iii) attractiveness of alternative job opportunities for the salesperson. We conclude with a discussion of the implications of the theory for managing salesforce compensation plans.salesforce compensation, agency theory, salary and commission plans, salesforce management

Chromium stable isotope ratios show promise as indicators of Cr(VI) reduction in groundwater, but no published study has yet demonstrated that expected relationships between (53)Cr/(52)Cr and Cr(VI) concentration, position, and time occur in an actual groundwater plume. We present an extensive data set from a point-source plume in Berkeley, CA; data extend over 5 years and 14 locations covering the entire plume. We interpret the data using a Rayleigh distillation model with an effective fractionation factor that incorporates an intrinsic fractionation factor determined from incubations of site sediments and accounts for reservoir effects in the restricted subsurface zones where Cr(VI) reduction is thought to occur. The groundwater (53)Cr/(52)Cr and Cr(VI) concentration data are consistent with a scenario where the system has reached a steady state: Cr(VI) reduction continues, the extent of reduction at any point is constant over time, reduction proceeds to completion at the downgradient edge of the plume, and the plume is no longer advancing. The overall consistency of the results with a reasonable model for the site supports the use of Cr isotope-based estimates of reduction, but we discuss current uncertainties and limitations of the approach as well.

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Indirect network externality (INE) effect exists when the utility of a product increases with the greater availability of compatible complementary products. We demonstrate that INE effects can vary by product attributes, with externality-sensitive attributes gaining more from increased availability of complementary products than other attributes. Past research has assumed that the benefit of increased availability of complementary products (e.g., software) accrues to theproduct (e.g., hardware). Utilizing data covering a period from 1985 to 1995 on compact disc player prices, attributes, and CD titles releases, and using a hedonic price approach, we find significant positive interactions between CD title availability and two attributes of the CD player, namely, changer capacity and its oversampling rate. In addition to INE-attribute interactions, increased availability of CD titles is found to have a significant positive impact on the overall price of CD players, which is consistent with past research. Collectively, these effects of INE have helped reduce the yearly decline in the price of CD players. The finding that INE effects differentially affect different attributes can help managers in decisions such as pricing, timing of introduction, and changing the levels of INE-sensitive attributes.Indirect Network Externality, Hedonic Price, Externality Sensitive Attributes, CD Player Prices

Significant uranium (U) isotope fractionation has been observed during abiotic reduction of aqueous U, counter to the expectation that uranium isotopes are only fractionated by bioassociated enzymatic reduction. In our experiments, aqueous U is removed from solution by reductive precipitation onto the surfaces of synthetic iron monosulfide. The magnitude of uranium isotopic fractionation increases with decreasing aqueous U removal rate and with increasing amounts of neutrally charged aqueous Ca-U-CO species. Our discovery means that abiotic U isotope fractionation likely occurs in any reducing environment with aqueous Ca ≥ 1 mM, and that the magnitude of isotopic fractionation changes in response to changes in aqueous major ion concentrations that affect U speciation. Our results have implications for the study of anoxia in the ancient oceans and other environments.

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Cr stable isotope measurements can provide improved estimates of the extent of Cr(VI) reduction to less toxic Cr(III). The relationship between observed (53)Cr/(52)Cr ratio shifts and the extent of reduction can be calibrated by determining the isotopic fractionation factor for relevant reactions. Permeable reactive barriers (PRB) made of Fe(0) and in situ redox manipulation (ISRM) zones effectively remediate Cr-contaminated aquifers. Here, we determine the isotopic fractionations for dominant reductants in reactive barriers and reduced sediments obtained from an ISRM zone at the US DOE's Hanford site. In all cases, significant isotopic fractionation was observed; fractionation (expressed as ε) was -3.91‰ for Fe(II)-doped goethite, -2.11‰ for FeS, -2.65‰ for green rust, -2.67‰ for FeCO(3), and -3.18‰ for ISRM zone sediments. These results provide a better calibration of the relationship between Cr isotope ratios and the extent of Cr(VI) reduction and aid in interpretation of Cr isotope data from systems with reactive barriers.

In situ recovery (ISR) uranium (U) mining mobilizes U in its oxidized hexavalent form (U(VI)) by oxidative dissolution of U from the roll-front U deposits. Postmining natural attenuation of residual U(VI) at ISR mines is a potential remediation strategy. Detection and monitoring of naturally occurring reducing subsurface environments are important for successful implementation of this remediation scheme. We used the isotopic tracers (238)U/(235)U (δ(238)U), (234)U/(238)U activity ratio, and (34)S/(32)S (δ(34)S), and geochemical measurements of U ore and groundwater collected from 32 wells located within, upgradient, and downgradient of a roll-front U deposit to detect U(VI) reduction and U mobility at an ISR mining site at Rosita, TX, USA. The δ(238)U in Rosita groundwater varies from +0.61‰ to -2.49‰, with a trend toward lower δ(238)U in downgradient wells. The concurrent decrease in U(VI) concentration and δ(238)U with an ε of 0.48‰ ± 0.08‰ is indicative of naturally occurring reducing environments conducive to U(VI) reduction. Additionally, characteristic (234)U/(238)U activity ratio and δ(34)S values may also be used to trace the mobility of the ore zone groundwater after mining has ended. These results support the use of U isotope-based detection of natural attenuation of U(VI) at Rosita and other similar ISR mining sites.