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Abstract. The Columbia River Treaty (CRT) signed between the United States and Canada in 1961 is known as one of the most successful transboundary watertreaties. Under continued cooperation, both countries equitably share collective responsibilities of reservoir operations and flood control andhydropower benefits from treaty dams. As the balance of benefits is the key factor of cooperation, future cooperation could be challenged byexternal social and environmental factors which were not originally anticipated or change in the social preferences of the two actors. To understandthe robustness of cooperation dynamics, we address two research questions. (i) How does social and environmental change influence cooperationdynamics? (ii) How do social preferences influence the probability of cooperation for both actors? We analyzed infrastructural, hydrological,economic, social, and environmental data to inform the development of a socio-hydrological system dynamics model. The model simulates the dynamicsof flood control and hydropower benefit sharing as a function of the probability to cooperate, which in turn is affected by the share ofbenefits. The model is used to evaluate scenarios that represent environmental and institutional change and changes in political characteristicsbased on social preferences. Our findings show that stronger institutional capacity ensures equitable sharing of benefits over the long term. Under the current CRT, the utility of cooperation is always higher for Canada than non-cooperation, which is in contrast to the United States. The probability tocooperate for each country is lowest when they are self-interested but fluctuates in other social preference scenarios. 

For quantum-confined nanomaterials, size dispersion causes a static broadening of spectra that has been difficult to measure and invalidates all-optical methods for determining the maximum photovoltage that an excited state can generate. Using femtosecond two-dimensional (2D) spectroscopy to separate size dispersion broadening of absorption and emission spectra allows a test of single-molecule generalized Einstein relations between such spectra for colloidal PbS quantum dots. We show that 2D spectra and these relations determine the thermodynamic standard chemical potential difference between the lowest excited and ground electronic states, which gives the maximum photovoltage. Further, we find that the static line broadening from many slightly different quantum dot structures allows single-molecule generalized Einstein relations to determine the average single-molecule linewidth from Stokes’ frequency shift between ensemble absorption and emission spectra. 

Abstract Unreliable public water supplies cause human hardships and are still common worldwide. Households often deal with the issue by adopting various coping strategies that are representative of economic decentralization (e.g., using private wells, sourcing from third‐party vendors) and political decentralization (e.g., making petitions to a public provider). There is growing interest in these user‐level decentralized coping strategies, but their relative effects on provider's behavior and the long‐term sustainability of public water supply remain unclear. This puzzle has not been tackled using an experimental approach. This study reports a controlled behavioral experiment conducted to test the relative effectiveness of different coping strategies on infrastructure quality and users‐provider cooperation in the context of agricultural water supply. We tested experimental treatments involving two classes of coping strategies:exitandvoice. The exit option represents users' shift to an alternative water source. The voice option represents users' direct effort to influence a public irrigation service provider. We recruited 272 human subjects into our 4‐player experiment (one provider and three users) and observed and compared their decisions under four treatments (exit, voice, their combination, and no options). The results show that the voice option leads to improved outcomes compared to other choices that include the exit option, suggesting that contrary to previously thought, the exit option can be detrimental to users‐provider cooperation. We also observed that a user tends to cooperate more (pay and use the public service) when other users do the same. 

An intrinsically phase-stable Sagnac interferometer is introduced for enhanced sensitivity detection in partially collinear two-dimensional spectroscopy in the short-wave IR. The sensitivity and phase accuracy of the apparatus are demonstrated on the dye IR-26.