Matching Contributions and the Voluntary Provision of a Pure Public Good: Experimental Evidence

Laboratory experiments are used to study the voluntary provision of a pure public good in the presence of an anonymous external donor. The external funds are used in two different settings, lump-sum matching and one-to-one matching, to examine how allocations to the public good are affected. The experimental results reveal that allocations to the public good under lumpsum matching are significantly higher, and have significantly lower within-group dispersion, relative to one-to-one matching and a baseline setting without external matching funds.public goods, free riding, laboratory experiments

Comparing Small-Group and Individual Behavior in Lottery-Choice Experiments

Lottery-choice experiments are conducted to compare risk preferences revealed by three-person groups versus isolated individuals. A lottery-choice experiment consists of a menu of paired lottery choices structured so that the crossover point from a low-risk to a high-risk lottery can be used to infer the degree of risk aversion. A between-subjects experiment of group versus individual lottery-choice decisions reveal that there is not a significant difference in the average crossover point, but lottery choices are affected by a significant interaction between subject composition (individual or group) and lottery winning percentage. Also, a three-phased individual-group-individual sequenced experiment reveals that the count of safe lotteries chosen by groups is, on average, significantly greater than the mean of the individual members. Finally, making a phase-two group decision has a significant impact on subsequent phase-three individual decisions relative to the initial phase-one (individual) decisions.lab experiments, risk preferences, group decisions

Comparing Small-Group and Individual Behavior in Lottery-Choice Experiments

Lottery-choice experiments are conducted to compare risk preferences revealed by three-person groups versus isolated individuals. A lottery-choice experiment consists of a menu of paired lottery choices structured so that the crossover point from a low-risk to a high-risk lottery can be used to infer the degree of risk aversion. A between-subjects experiment of group versus individual lottery-choice decisions reveal that there is not a significant difference in the average crossover point, but lottery choices are affected by a significant interaction between subject composition (individual or group) and lottery winning percentage. Also, a three-phased individual-group-individual sequenced experiment reveals that the count of safe lotteries chosen by groups is, on average, significantly greater than the mean of the individual members. Finally, making a phase-two group decision has a significant impact on subsequent phase-three individual decisions relative to the initial phase-one (individual) decisions.lab experiments, risk preferences, group decisions

9-Phenyl-3,4,4a,9a-Tetrahydrotriptycene and 9-Phenyl-1,2,3,4,4a,9a-Hexahydrotriptycene

The structure of 9-phenyl-3,4,4a,9a-tetrahydrotriptycene, C26H22, (I), exhibits regiochemistry consistent with a stepwise mechanism for its formation from photocycloaddition of 1,3- cyclohexadiene and 9-phenylanthracene. Bond distances involving the bridgehead C atoms are similar in (I) and the hydrogenated derivative, 9-phenyl-1,2,3,4,4a,9a-hexahydrotriptycene, C26H24, (II), with bonds to the quaternary-C atoms exhibiting significant elongation [1.581 (2) A Ê in (I) and 1.585 (2) A Ê in (II)]. The molecular geometry precludes significant overlap between the phenyl groups and the interannular bonds in both compounds, indicating that the origin of the bond lengthening is steric in nature

[2,3:5,6]Dibenzo[2.2.2]octa-2,5,7-triene (C2/c) and [2,3:5,6]dibenzo[2.2.2]octa-2,5-diene

Two barrelene homologs are reported. Strain in the bicyclic framework of [2,3:5,6]dibenzo[2.2.2]octa-2,5,7- triene, (I) (C16H12), which is manifest in the deviations from ideality of the bond angles in the central bicyclic ringoSyStem and compression of the double bond [1.312 (3)A], is reduced in the more saturated derivative, [2,3:5,6]dibenzo[2.2.2]octa-2,5-diene, (II) (CI6H14), with the corresponding single bond being 1.5380 (19)A. The formation of isomorphs of (I) in both chiral (C2) and achiral (C2/c) space groups has implications for asymmetric syntheses involving solid (I) which rely on a non-centrosymmetric space group

[2,3:5,6]Dibenzo[2.2.2]octa-2,5,7-triene (C2/c) and [2,3:5,6]dibenzo[2.2.2]octa-2,5-diene

Two barrelene homologs are reported. Strain in the bicyclic framework of [2,3:5,6]dibenzo[2.2.2]octa-2,5,7- triene, (I) (C16H12), which is manifest in the deviations from ideality of the bond angles in the central bicyclic ringoSyStem and compression of the double bond [1.312 (3)A], is reduced in the more saturated derivative, [2,3:5,6]dibenzo[2.2.2]octa-2,5-diene, (II) (CI6H14), with the corresponding single bond being 1.5380 (19)A. The formation of isomorphs of (I) in both chiral (C2) and achiral (C2/c) space groups has implications for asymmetric syntheses involving solid (I) which rely on a non-centrosymmetric space group

1,3-Bi-9-anthrylpropane

The title compound, C31H24, with three molecules in the asymmetric unit. The crystal packing is mainly stabilized by weak C—H⋯π inter­actions in addition to van der Waals forces

1,4-Di-9-anthrylbutane

In the title compound, C32H26, the molecule has an inversion centre at the mid-point of the central C—C bond. Weak intermolecular C—H...π interactions help to stabilize the crystal structure