Field Experiments

2004 ◽  
Vol 42 (4) ◽  
pp. 1009-1055 ◽  
Author(s):  
Glenn W Harrison ◽  
John A List
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Trading Rules ◽  
Subject Pool ◽  
The Subject ◽  
Do So

Experimental economists are leaving the reservation. They are recruiting subjects in the field rather than in the classroom, using field goods rather than induced valuations, and using field context rather than abstract terminology in instructions. We argue that there is something methodologically fundamental behind this trend. Field experiments differ from laboratory experiments in many ways. Although it is tempting to view field experiments as simply less controlled variants of laboratory experiments, we argue that to do so would be to seriously mischaracterize them. What passes for “control” in laboratory experiments might in fact be precisely the opposite if it is artificial to the subject or context of the task. We propose six factors that can be used to determine the field context of an experiment: the nature of the subject pool, the nature of the information that the subjects bring to the task, the nature of the commodity, the nature of the task or trading rules applied, the nature of the stakes, and the environment that subjects operate in.

scholarly journals Why Economists Should Conduct Field Experiments and 14 Tips for Pulling One Off

2011 ◽  
Vol 25 (3) ◽  
pp. 3-16 ◽  
Author(s):  
John A List
Keyword(s):  
Field Experiment ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Experimental Methods ◽  
Economic Research ◽  
The Subject

In this introduction to the symposium, I first offer an overview of the spectrum of experimental methods in economics, from laboratory experiments to the field experiments that are the subject of this symposium. I then offer some thoughts about the potential gains from doing economic research using field experiments and my own mental checklist of 14 steps to improve the chances of carrying out an economics field experiment successfully.

Pakistan’s Development: Successes, Failures, and Future Tasks (Presidential Remarks)

1997 ◽  
Vol 36 (4I) ◽  
pp. 321-331
Author(s):  
Sarfraz Khan Qureshi
Keyword(s):  
Indian Subcontinent ◽  
General Meeting ◽  
The Past ◽  
Past Half Century ◽  
The Social ◽  
The Subject ◽  
Golden Jubilee ◽  
Freedom Movement ◽  
Past Half ◽  
Do So

It is an honour for me as President of the Pakistan Society of Development Economists to welcome you to the 13th Annual General Meeting and Conference of the Society. I consider it a great privilege to do so as this Meeting coincides with the Golden Jubilee celebrations of the state of Pakistan, a state which emerged on the map of the postwar world as a result of the Muslim freedom movement in the Indian Subcontinent. Fifty years to the date, we have been jubilant about it, and both as citizens of Pakistan and professionals in the social sciences we have also been thoughtful about it. We are trying to see what development has meant in Pakistan in the past half century. As there are so many dimensions that the subject has now come to have since its rather simplistic beginnings, we thought the Golden Jubilee of Pakistan to be an appropriate occasion for such stock-taking.

Concentration of Impurities during Melting of Snow Made from Secondary Sewage Effluent

1986 ◽  
Vol 18 (2) ◽  
pp. 151-156 ◽  
Author(s):  
R. Zapf-Gilje ◽  
S. O. Russell ◽  
D. S. Mavinic
Keyword(s):  
Potassium Chloride ◽  
Chloride Solution ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Low Cost ◽  
Sewage Effluent ◽  
Potassium Chloride Solution ◽  
Laboratory Results ◽  
Solution Field ◽  
Concentration Of Impurities

When snow is made from sewage effluent, the impurities become concentrated in the early melt leaving the later runoff relatively pure. This could provide a low cost method of separating nutrients from secondary sewage effluent. Laboratory experiments showed that the degree of concentration was largely independent of the number of melt freeze cycles or initial concentration of impurity in the snow. The first 20% of melt removed with it 65% of the phosphorus and 90% of the nitrogen from snow made from sewage effluent; and over 90% of potassium chloride from snow made from potassium chloride solution. Field experiments with a salt solution confirmed the laboratory results.

scholarly journals Axiomatization and Measurement of Quasi-Hyperbolic Discounting *

2014 ◽  
Vol 129 (3) ◽  
pp. 1449-1499 ◽  
Author(s):  
José Luis Montiel Olea ◽  
Tomasz Strzalecki
Keyword(s):  
Hyperbolic Discounting ◽  
Partial Identification ◽  
Axiomatic Characterization ◽  
Discount Factors ◽  
Elasticity Of Intertemporal Substitution ◽  
Trade Offs ◽  
Subject Pool ◽  
Identification Approach ◽  
The Subject

Abstract This article provides an axiomatic characterization of quasi-hyperbolic discounting and a more general class of semi-hyperbolic preferences. We impose consistency restrictions directly on the intertemporal trade-offs by relying on what we call “annuity compensations.” Our axiomatization leads naturally to an experimental design that disentangles discounting from the elasticity of intertemporal substitution. In a pilot experiment we use the partial identification approach to estimate bounds for the distributions of discount factors in the subject pool. Consistent with previous studies, we find evidence for both present and future bias.

Mate availability facilitates cannibalistic behaviour in a nest brooding fish: effects of timing during the brood cycle

Behaviour ◽  
2011 ◽  
Vol 148 (2) ◽  
pp. 247-264 ◽  
Author(s):  
Masanori Kohda ◽  
Nobuhiro Ohnishi ◽  
Noboru Okuda ◽  
Tomohiro Takeyama ◽  
Omar Myint
Keyword(s):  
Laboratory Experiments ◽  
Gravid Female ◽  
Theoretical Models ◽  
Filial Cannibalism ◽  
Mate Availability ◽  
Stimulus Female ◽  
Trade Offs ◽  
Future Reproduction ◽  
Cannibalistic Behaviour ◽  
The Subject

AbstractFilial cannibalism, eating one's own viable offspring, is accepted as an adaptive response to trade-offs between current and future reproduction. Theoretical models predict that high mate availability may induce more filial cannibalism, but this prediction is rarely tested. To examine this prediction, we performed laboratory experiments using the nest breeding goby Rhinogobius flumineus. Subject males were allowed to mate with a gravid female and care for the broods. A separate gravid female housed in a small cage (stimulus-female) was shown to the subject males at one of three different points during the brood cycle: prior to spawning, within 1 day after spawning and 1 week after spawning. Empty cages were shown as a control. Males that were shown the stimulus-female before spawning cannibalised more eggs than control males. In contrast, males that were shown the stimulus-females after spawning cannibalised as few eggs as control males did. Additionally, males that were shown the stimulus-female prior to spawning did not court females more intensively than other males. Thus, we suggest that the presence of an additional mate, rather than energy expenditure associated with courtship directed toward an additional mate, can facilitate males to cannibalise their eggs.

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

Equity and certainty in contract law

Acta Juridica ◽  
2021 ◽  
Vol 2021 ◽  
pp. 141-176
Author(s):  
F Brand
Keyword(s):  
Supreme Court ◽  
Contract Law ◽  
Constitutional Court ◽  
High Court ◽  
Contractual Relationships ◽  
The Supreme Court ◽  
The Subject ◽  
Court Of Appeal ◽  
Do So

The role of abstract values such as equity and fairness in our law of contract has been the subject of controversy for a number of years. In 2002 the Supreme Court of Appeal took the position that these values do not constitute self-standing grounds for interfering with contractual relationships. Despite this being consistently maintained by the SCA in a number of cases, some High Court judges deviated from this position on the basis that they were permitted to do so by some minority judgments and obiter dicta in the Constitutional Court. The uncertainty thus created has fortunately now been removed by the judgment of the Constitutional Court in Beadica v The Trustees for the Time being of the Oregon Trust.

VIII.—High-Level Terraces in Norway

1877 ◽  
Vol 4 (2) ◽  
pp. 72-75 ◽  
Author(s):  
J. R. Dakyns
Keyword(s):  
Physical Geography ◽  
The Press ◽  
Scientific Opinion ◽  
The Subject ◽  
High Level ◽  
Do So

In the summer of 1872 I visited Norway, and wrote the following brief notice of certain high-level terraces immediately on my return to England, but kept it back that I might first consult some papers on Norwegian terraces that had appeared in the closing numbers of “Scientific Opinion”; these I was not able to meet with for so long a time that I gave up the idea of sending my notice to the press. I am now induced to do so, because I see that the subject of the parallel roads of Glenroy still occupies the attention of geologists, and it may induce some one next summer to examine minutely the Dovre terraces and sand-heaps and their relation to the physical geography of the district. I was merely able to make a flying visit to them, which I delayed my party to do, because they caught my eye so forcibly, as we were driving along the valley.

Toxæmia in the Etiology of Mental Disease. a Discussion opened

1902 ◽  
Vol 48 (202) ◽  
pp. 434-450 ◽  
Author(s):  
T. S. Clouston
Keyword(s):  
Nerve Cell ◽  
General Trend ◽  
Mental Disease ◽  
The Other ◽  
British Association ◽  
Younger Men ◽  
Full Knowledge ◽  
The Subject ◽  
Definition Of ◽  
Do So

Dr. Clouston said that when he suggested toxæmia to the secretary as a suitable subject for a discussion at this meeting he had not intended to be the first speaker, because his object was to bring out more fully the views of the younger members who had recently committed themselves so strongly to the toxæmic and bacterial etiology of insanity, and so to get light thrown on some of the difficulties which he and others had felt in applying this theory to many of their cases in practice. It was not that he did not believe in the toxic theory as explaining the onset of many cases, or that he under-rated its importance, but that he could not see how it applied so universally or generally as some of the modern pathological school were now inclined to insist on. He knew that it was difficult for those of the older psychological and clinical school to approach the subject with that full knowledge of recent bacteriological and pathological doctrine which the younger men possessed, or to breathe that all-pervading pathological atmosphere which they seemed to inhale. He desired to conduct this discussion in an absolutely non-controversial and purely scientific spirit. To do so he thought it best to put his facts, objections, and difficulties in a series of propositions which could be answered and explained by the other side. He thought it important to define toxæmia, but should be willing to accept Dr. Ford Robertson's definition of toxines, viz., “Substances which are taken up by the (cortical nerve) cell and then disorder its metabolism.” He took the following extracts from his address at the Cheltenham meeting of the British Association (1) as representing Dr. Ford Robertson's views and the general trend of much investigation and hypothesis on the Continent.

scholarly journals Everything You Always Wanted to Know about β3-AR * (* But Were Afraid to Ask)

Cells ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 357 ◽  
Author(s):  
Giorgia Schena ◽  
Michael J. Caplan
Keyword(s):  
Adrenergic Receptor ◽  
Species Differences ◽  
Current Clinical Practice ◽  
Substantial Body ◽  
Cellular Models ◽  
Wide Range ◽  
The Subject ◽  
And Function ◽  
Novel Therapeutic ◽  
Do So

The beta-3 adrenergic receptor (β3-AR) is by far the least studied isotype of the beta-adrenergic sub-family. Despite its study being long hampered by the lack of suitable animal and cellular models and inter-species differences, a substantial body of literature on the subject has built up in the last three decades and the physiology of β3-AR is unraveling quickly. As will become evident in this work, β3-AR is emerging as an appealing target for novel pharmacological approaches in several clinical areas involving metabolic, cardiovascular, urinary, and ocular disease. In this review, we will discuss the most recent advances regarding β3-AR signaling and function and summarize how these findings translate, or may do so, into current clinical practice highlighting β3-AR’s great potential as a novel therapeutic target in a wide range of human conditions.

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