Does One Contribution Come at the Expense of Another? Empirical Evidence on Substitution Between Charitable Donations

In this paper I estimate and describe the extent to which an individual's charitable donation to one cause displaces his or her giving to another cause. I use the 2001 and 2003 waves of the Panel Study of Income Dynamics (PSID), in conjunction with the Center on Philanthropy Panel Study (COPPS). This is the first useful major source of panel data on giving to multiple causes. I control for individual-fixed effects and use "college-reunion year" as an instrument for giving to education. I find an economically and statistically significant level of substitution. I also analyze the net effect of shocks to giving to one category on giving to all other categories - testing the extremes of a fixed purse (perfect crowding-out) and zero-crowding-out. While the uninstrumented regressions can generally reject perfect crowding out, the instrumental results (with larger error bounds) do not. I also find a greater level of substitution for "large givers" than for those who make smaller donations. This points to a model with heterogenous motivations for giving: small givers may be driven by shocks and reputation concerns, while for larger givers charities are imperfect substitutes in providing "warm glow" utility.

Stochastic Income and Conditional Generosity

We study how other-regarding behavior extends to environments with uncertain income and conditional commitments. Should fundraisers ask a banker to donate "if he earns a bonus" or wait and ask after the bonus is known? Standard EU theory predicts these are equivalent; loss-aversion and signaling models both predict a larger commitment before the bonus is known; theories of affect predict the reverse. In field and lab experiments, we allow people to donate from lottery winnings, varying whether they decide before or after learning the lottery's outcome. Males are more generous when making conditional donations before knowing the outcome, while females' donations are unaffected. Males also commit more in treatments where income is certain but the donation's collection is uncertain. This supports a signaling explanation: it is cheaper to commit to donate before the uncertainty is unresolved, thus a larger donation is required to maintain a positive image. This has implications for experimental methodology, for fundraisers, and for our understanding of pro-social behavior

Three-dimensional view of ultrafast dynamics in photoexcited bacteriorhodopsin

Bacteriorhodopsin (bR) is a light-driven proton pump. The primary photochemical event upon light absorption is isomerization of the retinal chromophore. Here we used time-resolved crystallography at an X-ray free-electron laser to follow the structural changes in multiphoton-excited bR from 250 femtoseconds to 10 picoseconds. Quantum chemistry and ultrafast spectroscopy were used to identify a sequential two-photon absorption process, leading to excitation of a tryptophan residue flanking the retinal chromophore, as a first manifestation of multiphoton effects. We resolve distinct stages in the structural dynamics of the all-trans retinal in photoexcited bR to a highly twisted 13-cis conformation. Other active site sub-picosecond rearrangements include correlated vibrational motions of the electronically excited retinal chromophore, the surrounding amino acids and water molecules as well as their hydrogen bonding network. These results show that this extended photo-active network forms an electronically and vibrationally coupled system in bR, and most likely in all retinal proteins

Does One Charitable Contribution Come at the Expense of Another?

This paper defines, discusses, and measures “expenditure substitution” in charitable giving. Motivated by a model of conditional demand, I consider the extent to which a “temporary shock” that increases an individual's donation to one cause by a particular amount displaces her gifts to other charitable causes. I use the 2001-2007 waves of the PSID/COPPS, the first data set of its kind, to identify this. Households that give more to one type of charity tend to give more to others. However, many of the correlations between the residuals after fixed-effects regressions are negative and significant, particularly for larger donors and for certain categories of charitable giving. Given plausible econometric assumptions, the negative correlations are strong evidence of expenditure substitution. Overall, these results suggest heterogeneous motivations for giving: small givers may be mainly driven by temporary shocks and personal appeals while larger givers may have concave multi-charity warm-glow preferences.

Peru's Downstream Natural Gas Sector : A Preliminary Assessment

This study assesses the natural gas market in Peru. In the process of evaluating the downstream market, the study identifies opportunities for meeting the Government s aspirational goals with respect to energy and natural gas development, including the efficient use of natural gas in the power and other sectors, strengthening and coordinating national energy planning for the gas sector, infrastructure development and prospects for decentralization of the natural gas market in Peru, and the potential of natural gas pricing reforms for the promotion of hydroelectricity and other renewable energy sources. This report is divided into five chapters. Chapter I describes the context in which this study was prepared. Chapter II presents a history of the natural gas sector and the Government of Peru s policy objectives to increase the use of natural gas in the domestic economy. Chapter III presents potential new markets for natural gas within the present context of the natural gas industry and the Peruvian economy. Chapter IV describes findings, issues, and options for improving Peru s downstream natural gas sector, including a discussion of the consistency between the Government s objectives and its policies for the sector. Chapter V sets out the conclusions of the study

Predicting replication outcomes in the Many Labs 2 study

Understanding and improving reproducibility is crucial for scientific progress. Prediction markets and related methods of eliciting peer beliefs are promising tools to predict replication outcomes. We invited researchers in the field of psychology to judge the replicability of 24 studies replicated in the large scale Many Labs 2 project. We elicited peer beliefs in prediction markets and surveys about two replication success metrics: the probability that the replication yields a statistically significant effect in the original direction (p<0.001), and the relative effect size of the replication. The prediction markets correctly predicted 75% of the replication outcomes, and were highly correlated with the replication outcomes. Survey beliefs were also significantly correlated with replication outcomes, but had higher prediction errors. The prediction markets for relative effect sizes attracted little trading and thus did not work well. The survey beliefs about relative effect sizes performed better and were significantly correlated with observed relative effect sizes. These results suggest that replication outcomes can be predicted and that the elicitation of peer beliefs can increase our knowledge about scientific reproducibility and the dynamics of hypothesis testing