We present a multichip structure assembled with a medical-grade stainless-steel microelectrode array intended for neural recordings from multiple channels. The design features a mixed-signal integrated circuit (IC) that handles conditioning, digitization, and time-division multiplexing of neural signals, and a digital IC that provides control, bandwidth reduction, and data communications for telemetry toward a remote host. Bandwidth reduction is achieved through action potential detection and complete capture of waveforms by means of onchip data buffering. The adopted architecture uses high parallelism and low-power building blocks for safety and long-term implantability. Both ICs are fabricated in a CMOS 0.18-mum process and are subsequently mounted on the base of the microelectrode array. The chips are stacked according to a vertical integration approach for better compactness. The presented device integrates 16 channels, and is scalable to hundreds of recording channels. Its performance was validated on a testbench with synthetic neural signals. The proposed interface presents a power consumption of 138 muW per channel, a size of 2.30 mm(2), and achieves a bandwidth reduction factor of up to 48 with typical recordings.

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This paper shows that if countries are farsighted when deciding whether to defect from a coalition, then the implementation of cleaner technologies, as embodied by a reduction in the emission per output ratio, may either improve or jeopardize the chances of reaching an international environmental agreement. A small change in the emission per output ratio can result in a discrete jump in the stable size of a coalition and global welfare evaluated under the stable coalition size. In the case of three countries, the grand coalition may be destabilized by the implementation of cleaner technologies, ultimately resulting in higher global emissions and lower global welfare. In the case of more than three countries, implementing cleaner technologies may result in a discrete jump, either upward or downward, of the largest stable coalition size and welfare. We examine both, the case of a flow and that of a stock pollutant. In the latter case, we show that the higher the stock of pollution at the instant when the cleaner technology is implemented, the more likely that a grand coalition of three countries is destabilized. Measures that enhance the natural rate of decay of stock pollutants are shown to have similar effects on the size of stable coalitions to reductions in the emission per output ratio.

We survey the economics literature on International Environmental Agreements (IEAs). We classify the extant literature into the following categories: pure IEA games without linkages, which focus on a single externality stemming from global pollution; IEA games with side payments and issue linkages, which consider carrot or stick mechanisms to lure cooperators or punish defectors; political economy models, which examine intra-and intergovernmental issues that affect international negotiations; design issues of IEAs; behavioral factors, which affect the willingness of countries to cooperate; and additional externalities resulting from open economy issues and adaptation, which interact with the global pollution externality and affect the free-riding incentives of countries. Based on this classification of the literature, we attempt to identify conditions under which an * We would like to thank Rita Antar for her excellent research assistance. We appreciate insightful comments by two anonymous reviewers and the editors.