Free Riding in the Lab and in the Field

We run a public good experiment in the field and in the lab with (partly) the same subjects. The field experiment is a true natural field experiment as subjects do not know that they are exposed to an experimental variation. We can show that subjects' behavior in the classic lab public good experiment correlates with their behavior in the structurally comparable public good treatment in the field but not with behavior in any of two control treatments we ran in the field. This effect is also economically significant. We conclude that a) the classic lab public good experiment captures important aspects of structurally equivalent real life situations and b) that behavior in lab and field at least in our setting is driven by the same underlying forces.Field and Lab Experiments; External Validity; Public Goods; Team Production

APEX: A Prime EXperiment at Jefferson Lab

APEX is an experiment at Thomas Jefferson National Accelerator Facility (JLab) in Virginia, USA, that searches for a new gauge boson ($A^\prime$) with sub-GeV mass and coupling to ordinary matter of $g^\prime \sim (10^{-6} - 10^{-2}) e$. Electrons impinge upon a fixed target of high-Z material. An $A^\prime$ is produced via a process analogous to photon bremsstrahlung, decaying to an $e^+ e^-$ pair. A test run was held in July of 2010, covering $m_{A^\prime}$ = 175 to 250 MeV and couplings g^\prime/e \; \textgreater \; 10^{-3}. A full run is approved and will cover $m_{A^\prime} \sim$ 65 to 525 MeV and g^\prime/e \; \textgreater \; 2.3 \times10^{-4}.Comment: Contributed to the 8th Patras Workshop on Axions, WIMPs and WISPs, Chicago, July 18-22, 2012. 4 pages, 4 figure

Some differences in revealed behaviour under different inquiry methods

The experiment presented in this paper has two aims, both methodological. First, we want to check for the role of what we may call (after Carpenter et al., 2006) the they came to play effect. Second, we want to test whether the lab outcomes are confirmed by a questionnaire on a hypothetical similar scenario. In order to pursue our aims, we design an experiment made of four treatments: a lab-experiment with strategy method, a lab-experiment without strategy method, a questionnaire with strategy method and a questionnaire without strategy method. We may conclude that the lab results are definitively more reliable than the questionnaire ones only if you manage, in one way or the other, to get rid of the bias induced by the they came to play effect: a post-experiment questionnaire, containing explicit questions on the matter, may be a device.Experiments, questionnaire, come to play effect, strategy method

Fermentation Quality and in Vitro Nutrient Digestibility of Fresh Rice Straw-Based Silage Treated with Lactic Acid Bacteria

The aim of the experiment was to evaluate fermentation characteristics and in vitro nutrient digestibility of fresh rice straw-based silage ensiled with addition of epiphytic lactic acid bacteria (LAB) inoculant. The experiment was arranged in a completely randomized design, with 2 × 2 factorial arrangement of treatments. The first factor was the ratio of fresh rice straw (FRS), tofu waste (TW) and cassava waste (CW) consisted of two levels i.e., 40 : 20 : 40 and 40 : 25 : 35, on dry matter (DM) basis). The second factor was the level of LAB inoculant with two levels ie., 0 and 20 mL/kg FM. The treatments were (A) FRS + TW + CW with the ratio of 40 : 20 : 40, without LAB inoculant; (B) FRS + TW + CW with the ratio of 40 : 20 : 40 + LAB inoculant; (C) FRS + TW + CW with the ratio of 40 : 25 : 35, without LAB inoculant; (D) FRS + TW + CW with ratio of 40 : 25 : 35 + LAB inoculant. Results showed that addition of LAB inoculant in silage increased lactic acid concentration (P0.05) on chemical composition, fermentation quality of silage and in vitro digestibility. It was concluded that mixture silage with ratio of 40 : 20 : 40 with the addition of LAB inoculant had the best fermentation quality and nutrient digestibility than other silages

How eBay Sellers set “Buy-it-now†prices - Bringing The Field Into the Lab

In this paper we introduce a new type of experiment that combines the advantages of lab and field experiments. The experiment is conducted in the lab but using an unchanged market environment from the real world. Moreover, a subset of the standard subject pool is used, containing those subjects who have experience in conducting transactions in that market environment. This guarantees the test of the theoretical predictions in a highly controlled environment and at the same time enables not to miss the specific features of economic behavior exhibited in the field. We apply the proposed type of experiment to study seller behavior in online auctions with a Buy-It-Now feature, where early potential bidders have the opportunity to accept a posted price offer from the seller before the start of the auction. Bringing the field into the lab, we invited eBay buyers and sellers into the lab to participate in a series of auctions on the eBay platform. We investigate how traders' experience in a real market environment influences their behavior in the lab and whether abstract lab experiments bias subjects' behavior.online auctions; experiments; buyout prices

Immoral criminals? An experimental study of social preferences among prisoners.

This paper studies the pro-social preferences of criminals by comparing the behavior of a group of prisoners in a lab experiment with the behavior of a benchmark group recruited from the general population. We find a striking similarity in the importance the two groups attach to pro-social preferences in both in strategic and non-strategic situations. This result also holds when the two groups interact. Data from a large internet experiment,matched with official criminal records, suggest that our main finding from the lab experiment is not influenced by the additional scrutiny experienced by participants in prison.Pro-social preferences; Criminals; Lab experiment

Inbreeding Affects on Beetle Clustering

The Red Flour Beetle (Tribolium castaneum; Coleoptera: Tenebrionidae) is a common pest in many grain mills (Baldwin and Fasulo 2010) and found wherever grains or other dried foods are stored (Schröder 2008). The Red Flour Beetle ”facilitates genetic analysis with ease of culture, a short life cycle, high fecundity and facility for genetic crosses, allowing efficient genetic screens (Schröder 2008).” This can allow for them to have a strong genetic code the longer that they are bred in the lab. So, for this experiment we will be trying to see what affect inbreeding has on the aggregation behavior in the Red Flour Beetle. The purpose of this experiment is to see how genetic background influences grouping behavior. Two different strains of Tribolium castaneum were used in this experiment. The one strain used was the Hudson Red Flour Beetle which originates from Hudson, Kansas. They have been bred in the lab for 10 years. The other beetle that was used is the NDG Red Flour Beetle, which originates from Manitoba, Canada and has been in the lab 30 years. After completing this experiment, our findings are that the Hudson are considerably more light sensitive than the Hudson and as soon as light hit them they become very active. There was a noticeably higher percentage of NDG beetles that would cluster together and when they clustered they only clustered with their own strain. This leads us to believe that the NDG beetles have stronger aggregation behavior due to the significant amount of time they have been in lab breeding, compared to the Hudson beetle. The inbreeding that occurred might of allowed for the beetles to develop a more similar genetic code that allows them to group together more easily