A key organizational decision for retailers is whether to self-distribute or rely on a wholesaler-supplied network and yet little is known about the impact of this strategic choice on store-level productivity. We estimate a stochastic frontier model for food retailers that accounts for selectivity effects linked to the choice of distribution strategy. We find that adoption of data-sharing technologies has a positive impact on store-level gross margins of stores in self-distributing chains. Technical inefficiency among U.S. food retailers leads to a gross margin that is around $5,000 less for a conventional food retailer and about $7,670 less for a supercenter.

Using data from a survey of Pennsylvania food processors, we investigate what firm-level characteristics make a processor more or less likely to buy agricultural inputs and ingredients though contracts. We find that over 20 percent of Pennsylvania processors use contracts, and over 44 percent of agricultural inputs (based on value) are purchased under contract. We also analyze the two related questions of what firm attributes, attitudes, or other factors make a firm more likely to use contracts at all, and what factors lead a processor who does contract to use them more intensively.

When using a willingness-to-pay (WTP) format in contingent valuation (CV) to value watershed restoration, respondents may protest by questioning why they should pay to clean up a pollution problem that someone else created. Using a sample selection interval data model based on Bhat (1994) and Brox, Kumar, and Stollery (2003), we found that the decision to protest and WTP values were correlated. Protest sample selection bias resulted in a 300 percent overestimate of mean WTP per respondent. Using different ad hoc treatments of protesters, protest bias resulted in moderate effects (−10 percent to +14 percent) after controlling for sample selection bias.

Estimating how the use of production contracts affects farm productivity is difficult when unobservable factors are correlated with both the decision to contract and productivity. To account for potential selection bias, this study uses the local availability of production contracts as an instrument for whether a farm uses a contract in order to estimate the impact of contract use on total factor productivity. Results indicate that use of a production contract is associated with a large increase in productivity for feeder-to-finish hog farms in the United States. The instrumental variable method makes it credible to assert that the observed association is a causal relationship rather than simply a correlation.

Worldwide, dating rock art is difficult to achieve because of the frequent lack of datable material and the difficulty of removing contamination from samples. Our research aimed to select the paints that would be the most likely to be successfully radiocarbon dated and to estimate the quantity of paint needed depending on the nature of the paint and the weathering and alteration products associated with it. To achieve this aim, a two-step sampling strategy, coupled with a multi-instrument characterization (including SEM-EDS, Raman spectroscopy, and FTIR spectroscopy analysis) and a modified acid-base-acid (ABA) pretreatment, was created. In total, 41 samples were dated from 14 sites in three separate regions of southern Africa. These novel protocols ensure that the 14C chronology produced was robust and could also be subsequently applied to different regions with possible variations in paint preparation, geology, weathering conditions, and contaminants.

During the Middle Paleolithic period, carnivores and hominids periodically occupied the same areas at different times and each predator generated significant palimpsests, rendering difficult their archaeological interpretation. Teixoneres Cave, a carnivore den site, located in the northeastern part of the Iberian Peninsula, demonstrates that it is possible to overcome these problems by using a careful strategy in selecting samples for radiocarbon dating, in order to produce an accurate chronology of the site in question and certainly attest the human occupation.

Probit analysis identified factors that influence the adoption of precision farming technologies by Southeastern cotton farmers. Younger, more educated farmers who operated larger farms and were optimistic about the future of precision farming were most likely to adopt site-specific information technology. The probability of adopting variable-rate input application technology was higher for younger farmers who operated larger farms, owned more of the land they farmed, were more informed about the costs and benefits of precision farming, and were optimistic about the future of precision farming. Computer use was not important, possibly because custom hiring shifts the burden of computer use to agribusiness firms.

This study compares an ordered probit model and a Tobit model with selection to take into account both true zero and protest zero bids while estimating the willingness to pay (WTP) for conservation easements in Macon County, NC. By comparing the two models, the ordered/unordered selection issue of the protest responses is analyzed to demonstrate how the treatment of protest responses can significantly influence WTP models. Both models consistently show that income and knowledge are positive and significant factors, while distance to poorer quality streams and duration of residency are negative and significant factors on WTP.

In this paper we examine the effect of innovation on job creation and job destruction in Spanish manufacturing. Our empirical analysis is based on firm-level longitudinal data from which we have information on employment and innovation activity. The estimation approach consists of a two-step procedure that takes into account the fact that firms endogenously choose positive, negative or zero growth in employment, in which the selection mechanism is an ordered probit. Our results point out the importance of innovation variables on employment growth: innovative firms create more jobs -and destroy fewer- than non-innovative, and the degree of technological effort has a strong positive effect on net employment creation.