Secure Implementation: Strategy-Proof Mechanisms Reconsidered

Strategy-proofness, requiring that truth-telling is a dominant strategy, is a standard concept in social choice theory. However, the concept of strategy-proofness has serious drawbacks. First, announcing one's true preference may not be a unique dominant strategy, and using the wrong dominant strategy may lead to the wrong outcome. second, almost all strategy-proof mechanisms have a continuum of Nash equilibria, most of which produce the wrong outcome. Third, experimental evidence shows that most of the strategy-proof mechanisms do not work well. We argue that a possible solution to this dilemma is to require double implementation in Nash equilibrium and in dominant strategies, which we call secure implementation. We characterize environments where secure implementation is possible, and compare it with dominant strategy implementation. An interesting example of secure implementation is a Groves mechanism when preferences are single-peaked.

Secure Implementation

Strategy-proofness, requiring that truth-telling is a dominant strategy, is a standard concept in social choice theory. However, this concept has serious drawbacks. In particular, many strategy-proof mechanisms have multiple Nash equilibria, some of which produce the wrong outcome. A possible solution to this problem is to require double implementation in Nash equilibrium and in dominant strategies, i.e., secure implementation. We characterize securely implementable social choice functions, and compare our results with dominant strategy implementation. In standard quasi-linear environments with divisible private or public goods, there exist Pareto efficient (non-dictatorial) social choice functions that can be securely implemented. But in the absence of side-payments, secure implementation is incompatible with Pareto efficiency.

Secure implementation

Strategy-proofness, requiring that truth-telling be a dominant strategy, is a standard concept in social choice theory. However, this concept has serious drawbacks. In particular, many strategy-proof mechanisms have multiple Nash equilibria, some of which produce the wrong outcome. A possible solution to this problem is to require double implementation in Nash equilibrium and in dominant strategies, i.e., secure implementation. We characterize securely implementable social choice functions and investigate the connections with dominant strategy implementation and robust implementation. We show that in standard quasi-linear environments with divisible private or public goods, there exist surplus-maximizing (non-dictatorial) social choice functions that can be securely implemented.Nash implementation, robust implementation, secure implementation, strategy-proofness

Reduction of diphenylacetylene using Al powder in the presence of noble metal catalysts in water

Diphenylacetylenes can be reduced to the corresponding diphenylethanes (2) in water in excellent yield using Al powder and Pd/C at 60 °C for 3 h in a sealed tube. In addition, the complete reduction of both aromatic rings required 80 °C for 15 h with Al powder in the presence of Pt/C. However, the nature of hydrogenated product formed was found to be strongly influenced by the reaction temperature, time, volume of water and the amount of catalyst being employed

Direct evidence of a blocking heavy atom effect on the water-assisted fluorescence enhancement detection of Hg²⁺ based on a ratiometric chemosensor

At the current stage of chemosensor chemistry, the critical question now is whether the heavy atom effect caused by HTM ions can be blocked or avoided. In the present work, we provide unequivocal evidence to confirm that the heavy atom effect of Hg²⁺ is inhibited by water and other solvent molecules based on results using the chemosensor L. Most importantly, the heavy atom effect and blocking thereof were monitored within the same system by the use of ratiometric fluorescence signal changes of the pyrene motif. These observations not only serve as the foundation for the design of new ‘turn-on’ chemosensors for HTM ions, but also open up new opportunities for the monitoring of organic reactions

Secure Implementation Experiments: Do Strategy-proof Mechanisms Really Work?

Strategy-proofness, requiring that truth-telling is a dominant strategy, is a standard concept used in social choice theory. Saijo et al. (2003) argue that this concept has serious drawbacks. In particular, many strategy-proof mechanisms have a continuum of Nash equilibria, including equilibria other than dominant strategy equilibria. For only a subset of strategy-proof mechanisms do the set of Nash equilibria and the set of dominant strategy equilibria coincide. For example, this double coincidence occurs in the Groves mechanism when preferences are single-peaked. We report experiments using two strategy-proof mechanisms. One of them has a large number of Nash equilibria, but the other has a unique Nash equilibrium. We found clear differences in the rate of dominant strategy play between the two.Experiment, Laboratory, Secure Implementation, Groves-Clarke, Pivotal, Learning

Secure Implementation Experiments: Do Strategy-proof Mechanisms Really Work?

Strategy-proofness, requiring that truth-telling is a dominant strategy, is a standard concept used in social choice theory. Saijo et al. (2003) argue that this concept has serious drawbacks. In particular, announcing one's true preference may not be a unique dominant strategy, and almost all strategy-proof mechanisms have a continuum of Nash equilibria. For only a subset of strategy-proof mechanisms do the set of Nash equilibria and the set of dominant strategy equilibria coincide. For example, this double coincidence occurs in the Groves mechanism when preferences are single-peaked. We report experiments using two strategy-proof mechanisms where one of them has a large number of Nash equilibria, but the other has a unique Nash equilibrium. We found clear differences in the rate of dominant strategy play between the two.

Impact of Ethnicities on Market Outcome: Results of Market Experiments in Kenya

We study market exchange in the laboratory by a multiethnic experiment in Kenya. The subjects of our experiment are of three ethnicities, Kikuyu, Luo, and Kalenjin. Our model contains two types of consumers and two kinds of commodities, and three competitive equilibria exist. The two equilibria with the lowest, and highest relative prices are beneficial for one type of the consumers, and the intermediate price gives an equitable allocation. The tatonnement dynamics however predict that relative prices diverge from the intermediate equilibrium towards the lowest equilibrium or the highest equilibrium depending on initial prices. In order to examine how much effect the ethnicities of subjects have on the equilibrium selection, we conducted manual experiments of pit market trading with different combinations of ethnicities of subjects. Our result shows strong support for the convergence to the intermediate equilibrium when Kalenjin subjects participated, whereas no such data are obtained without them. In addition, the frequencies of transactions with Kalenjin subjects were significantly less than that with the other subjects only, and the less frequent transactions resulted in the more efficient outcomes of the experimental market.Economic Experiment, Kenya, Pit Market, Perfect Competition, Multiple Equilibria

Reduction of phenylacetylenes using Raney Ni-Al alloy, Al powder in the presence of noble metal catalysts in water

Dedicated to Prof. Kenneth Laali on the occasion of his 66th birthday Received mm-dd-yyyy Accepted mm-dd-yyyy Published on line mm-dd-yyyy Dates to be inserted by editorial office Abstract The chemoselective reduction is based on the reaction of Raney Ni–Al alloy with Al powder in water which produces in situ hydrogen to utilize the hydrogenation of the targeted functional groups. Raney Ni–Al alloy with Al powder can reduce phenylacetylenes to the corresponding ethylbenzene (3) in water in excellent yield at 120 °C for 6 h in a sealed tube. In addition, the complete reduction of aromatic ring to ethylcyclohexane (4) required 60 °C for 12 h with Raney Ni–Al alloy, Al powder in the presence of Pt/C. The appropriate selection of the reaction conditions allowed the selective preparation of ethylbenzene as well as ethylcyclohexane from phenylacetylene. 1a : R = H ,1b : R = CH 3 , 1c : R = OCH 3 ,1d : R = C(CH 3)