Sunday, May 13, 2012
Bone marrow registries
"Now he is trying to repay that debt, with an effort that experts say may save the lives of both Nigerians and black Americans. In February, he helped start Nigeria’s national bone-marrow registry, the first in Africa outside South Africa. He is now raising money to start a cord-blood bank there.
Millions of Nigerians have blood cancers like leukemia or lymphoma, and about 4,000 black Americans die annually of them. Less than 20 percent of black Americans now find the perfect donor matches that could save their lives, while more than 70 percent of whites do. Without a registry and cord-blood bank, no Nigerians do.
“This is a slam-dunk, from my point of view,” Mr. Adebiyi said. “The U.S. registries are trying to figure out how to increase the population of minority donors; this is a solution they should be interested in.”
Becoming a donor is relatively simple nowadays; only a cheek swab is needed to test for a match. Donating rarely requires the painful hip punctures that used to be routine. Instead, an intravenous blood line runs through a cell separator after the donor takes drugs to push the stem cells into the bloodstream. The process is no more burdensome than dialysis, experts say.
But for African-Americans like Mr. Adebiyi, finding matches is particularly difficult. Blacks are less likely to register as donors; while blacks are 12.6 percent of the population, only 8 percent of registered donors are black.
“It’s lack of education about it, and mistrust of the medical system after scandals like Tuskegee,” said Shauna Melius, co-founder of Preserve Our Legacy, citing the Tuskegee, Ala., experiment in which government doctors recruited black farmers for research and let those with syphilis go untreated for decades. Her organization recruits donors at Harlem Hospital and through drives featuring black celebrities.
“Plus,” she added, “people are skeptical because you’re collecting DNA.”
Complicating the problem, blacks are more genetically diverse than whites. Anatomically modern Homo sapiens existed in Africa for 200,000 years before migrating north to Europe a little over 40,000 years ago, so all Europeans descend from the shallower end of the gene pool.
Sunday, January 19, 2014
Cash for Kidneys: The Case for a Market for Organs. Becker and Elias in the WSJ
Their 2007 JEP paper was called Introducing Incentives in the Market for Live and Cadaveric Organ Donations (slightly more direct link here).
Between then and now the number of people on the waiting list for kidneys has gone up. Their 2007 article has these sentences: "Almost 17,000 persons were waiting for a kidney transplant in 1990. But this number grew rapidly, so that about 65,000 persons were on this waiting list by the beginning of 2006."
This weekend's WSJ column starts with the sentence "In 2012, 95,000 American men, women and children were on the waiting list for new kidneys, the most commonly transplanted organ."
So, the arguments that they repeat have gotten stronger over time: the shortage of organs is costly in every sense, and could likely be relieved by allowing kidneys to be bought and sold by live donors, and allowing the purchase of organs from deceased potential donors, i.e. by repealing the part of the 1984 National Organ Transplant Act that makes such sales a felony in the United States. (Similar laws exist in most of the developed world: the only country that seems to have an explicitly legal market for kidneys is Iran, although many black and grey markets exist.)
So, why hasn't this argument made any headway, either in the U.S. or overseas? Is patient repetition of the argument the best way to make the case? I don't know the answers, but I think that the repugnance of organ sales is a subject worth studying, not just for science but also for those who might like to influence policy.
In the same issue of the JEP as Becker and Elias (2007) was my article Repugnance as a Constraint on Markets (more direct link here), which sought to understand not just the repugnance to kidney sales, but to many economic transactions, in different places and times, e.g. to charging interest on loans, or having markets for slaves or indentured servants. I noted that kidney exchange doesn't arouse the repugnance that sales do. I've since blogged about a lot of different repugnant transactions including compensation for donors (as of this writing my most recent post on transactions that some regard with repugnance is headlined Womb transplants in Sweden (where surrogacy is illegal)...)
Note that the prohibition on organ sales is not some law that remains on the books merely through inattention. This is illustrated by the recent events surrounding the tug of war over whether it might be legal to compensate (even) bone marrow donors. Briefly, the ninth circuit court of appeals issued a ruling that said that in some circumstances bone marrow donors could be compensated, but then the Department of Health and Human Services proposed regulations that would keep the ban in place. So the opposition to organ sales--even to compensating bone marrow donors--is alive and well.
But things don't go all in one direction. Bob Slonim reminds me that while we rely on unpaid donation of whole blood in the United States, most of our supply of blood plasma comes from paid donors.
I've participated in some efforts to understand better the repugnance to compensating organ donors, e.g. here's a survey with Steve Leider about who disapproves of kidney sales, and some correlates of such disapproval:
Leider, Stephen and Alvin E. Roth, ''Kidneys for sale: Who disapproves, and why? American Journal of Transplantation 10 (May), 2010, 1221-1227.
More recently, Muriel Niederle and I conducted a different sort of survey, which assessed the relative willingness of Americans to contemplate monetary rewards for the heroism associated with kidney donation:
"Niederle, Muriel and Alvin E. Roth, “Philanthropically Funded Heroism Awards for Kidney Donors?” forthcoming in Law & Contemporary Problems, 77:3, 2014.
Judd Kessler and I have a paper forthcoming in the American Economic Review papers and proceedings (May 2014) called "Getting More Organs for Transplantation," in which we summarize the issue this way:
"Kidney sales are often the leading example of a repugnant transaction cited by those who would put stricter limits on markets in general (e.g. Sandel 2012, 2013), because of their sense that such sales arouse widespread opposition. A representative sample survey of Americans conducted by Leider and Roth (2010) suggests that disapproval of kidney sales correlates with other socially conservative attitudes, but that it does not rise to the level of disapproval of other repugnant transactions such as prostitution. In addition, there is evidence that the manner of the payment to an organ donor may mitigate some of the repugnance concerns. Niederle and Roth (forthcoming 2014) find that payments to non-directed kidney donors are deemed more acceptable when they arise as a reward for heroism and public service than when they are viewed as a payment for kidneys."
That paper closes with this thought on the presently available options:
"While these potential donors could save thousands of additional lives, at current rates of medical need, these donors alone would not be able to supply all the demand. Consequently, we must continue working on numerous fronts to solve this growing problem. "
In summary, the issue of whether and how organ donors might be compensated is an important policy issue that also touches on an important and still poorly understood social science phenomenon. Repetition of the basic arguments may move the discussion forward as the background facts become more severe, and it's great to see the issue addressed in such a public forum as the WSJ. But it may also be that repetition of arguments is not enough. To make progress in the face of opposition, it seems likely to be useful to understand better the nature of the opposition.
Monday, September 1, 2014
Banks for blood and sperm
Very interesting. For example:
"What happened as the metaphor [of a bank] became more used in the 1950s and 1960s, was that a backlash developed against the market implications of the metaphor. The doctors and lay people who ran blood banks in the 1950s and 1960s, pushed the metaphor to its extremes—they told patients that each transfusion was a “loan” that needed to be repaid. Patients could repay in kind, or pay stiff replacements fees instead—fees that a bank could use to buy blood from a professional donor—always with the goal of keeping sufficient inventory.
The emphasis on buying and selling led blood banks into trouble in the courts—attorneys for patients injured from transfusions (which happened sometimes, if mismatched blood was given, or the blood contained a disease) argued that banked blood was a product. Product liability law was developing to find the manufacturer of a dangerous product liable even without negligence. Doctors, blood banks, and hospitals were horrified to have themselves considered product manufacturers. They began to backpedal from the banking metaphor by trying to make banked blood seem less like a product exchanged in markets.
What happened, with blood banks, and also with other kinds of banks, is that the banking metaphor and the backlash encouraged doctors, patients, and those of us who might be suppliers, to focus on one aspect—the supplier. Was the supplying body paid or unpaid? Paid suppliers, who were obviously entering into a market transaction, were treating their bodies as a source of private property, and were acting as though they were selling a product. Unpaid suppliers, were seen as giving gifts, out of altruism, and keeping themselves out of a market."
...
"In law, we thus divide body products into two categories: those which we legally mandate as gifts only—all organs—and everything else, which can be gifted or sold, at the discretion of the supplier. Organs is defined broadly—bone marrow, for example, is an “organ.” This means that bone marrow, which can now be extracted from the blood in a procedure similar to the way blood plasma is harvested, cannot be sold by anyone. (Blood plasma is routinely sold, by the way.)
...
"I argue in the book that the simple pay-suppliers/don’t-pay-suppliers approach to thinking about body products, which resulted from the banking metaphor, needs to be replaced with more nuanced thinking. Should we treat different types of organs (hearts v. bone marrow) differently? Can we think about compensation schemes that are not free markets, but are managed to support the public goals of increasing body-product supply? Can those schemes protect suppliers and recipients alike by keeping suppliers safe from exploitation, and recipients safe from diseased products? I use history to suggest that the answers can sometimes be yes. Body products used to be routinely paid for, and doctors thought about these potential problems and addressed them. Over time, we have forgotten this past, and come to assume that buying body products is always dangerous and bad.
I like to remind people that lots of altruistic gestures are compensated—the doctors, and nurses, and everyone who works on a transplant operation are all in caring professions. They are doing those jobs because they want to help people (at least we hope and assume so). But we wouldn’t suggest that they shouldn’t be paid because to offer payment for such efforts would be insulting or immoral or cause their altruistic tendencies to be replaced by mercenary concerns.
Yet that is how we treat organ supply—that offering money would do all those bad things. Why should the supplier of a body product be the only person in that life-saving supply chain who is not compensated? People might choose not to be compensated, but if they want to be, and if more folks will act as suppliers with that incentive, why not?
To give a more specific historical example, let’s think about mothers’ milk stations in the 1930s. At that time, in most cities, such a station existed. It was established and supervised by a doctor or doctors, and its daily operations were run by nurses. Lactating women came to the station to express their breast milk and were paid by the ounce. Payment was used to ensure an adequate supply. The supply was used for sick and/or premature infants who lack a maternal source of milk."
**************
In the meantime, here's a news article published around the same time, from the business side:
More blood banks merging to cut costs--Officials cite need for new model
"The proposed merger of Green Tree’s Institute for Transfusion Medicine with Florida-based OneBlood is the latest in a series of blood bank consolidations nationally, symptomatic of lean times for hospitals as they try to cut costs and reduce transfusions.
The deal, announced July 25, would create one of the largest blood banks in the country, with combined revenues of $480 million, if it goes through. The two firms jointly distribute nearly 2 million units of blood annually, serving 313 hospitals in eight states.
Only the American Red Cross would collect and distribute more blood."
Thursday, August 25, 2016
Compensating bone marrow (blood stem cell) donors: still in legal limbo
Thursday, September 29, 2016
It looks like paying donors of bone marrow/ blood stem cells will remain illegal...
View EO 12866 Meetings | Printer-Friendly Version Download RIN Data in XML |
HHS/HRSA | RIN: 0906-AB02 | Publication ID: Spring 2016 |
Title: Definition of Human Organ Under Section 301 of the National Organ Transplant Act of 1984 | |
Abstract:This final rule clarifies that peripheral blood stem cells are included in the definition of bone marrow under section 301 of the National Organ Transplantation Act of 1984, as amended and codified in 42 U.S.C. 274e. | |
Agency: Department of Health and Human Services(HHS) | Priority: Info./Admin./Other |
RIN Status: Previously published in the Unified Agenda | Agenda Stage of Rulemaking: Final Rule Stage |
Major: No | Unfunded Mandates: No |
CFR Citation: Not Yet Determined (To search for a specific CFR, visit the Code of Federal Regulations.) | |
Legal Authority: Pub. L. 109-129 Stem Cell Therapeutic and Research Act of 2005, as amended in 2010 by Pub. L. 111-264 |
Legal Deadline: None | ||||||||||||
Timetable:
|
Regulatory Flexibility Analysis Required: No | Government Levels Affected: Undetermined |
Small Entities Affected: No | Federalism: No |
Included in the Regulatory Plan: No | |
RIN Data Printed in the FR: No | |
Agency Contact: Dr. James Bowman Medical Director, Division of Transplantation Department of Health and Human Services Health Resources and Services Administration 5600 Fishers Lane, Room 12C-06, Rockville, MD 20857 Phone:301 443-4861 |
HT: Kim Krawiec
Sunday, January 1, 2017
Matchmaker Exchange: Matching genes and symptoms for patients with very rare diseases ("lonesome exomes")
But as more patients with very rare disease have their exome sequenced, there are patients with particular phenotypes and symptoms and "lonesome exomes," which have a suspect gene that may be responsible for their disease, which will remain only a suspect until more patients with that disease and that gene variant can be identified. These data are mostly in separate databases at different clinical research institutions.
That's where Matchmaker exchange comes in--it's a protocol for looking for patients with the same gene variants and the same diseases, so that matches can be made and the genes responsible for rare diseases can be identified.
Here's the paper:
Philippakis AA, Azzariti DR, Beltran S, Brookes AJ, Brownstein CA, Brudno M, Brunner HG, Buske OJ, Carey K, Doll C, Dumitriu S, Dyke SOM, den Dunnen JT, Firth HV, Gibbs RA, Girdea M, Gonzalez M, Haendel MA, Hamosh A, Holm IA, Huang L, Hurles ME, Hutton B, Krier JB, Misyura A, Mungall CJ, Paschall J, Paten B, Robinson PN, Schiettecatte F, Sobreira NL, Swaminathan GJ, Taschner PE, Terry SF, Washington NL, Züchner S, Boycott KM, Rehm HL. 2015. The Matchmaker Exchange: A Platform for Rare Disease Gene Discovery. Human Mutation, 36: 915–921. doi:10.1002/humu.22858
ABSTRACT: There are few better examples of the need for data sharing than in the rare disease community, where patients, physicians, and researchers must search for “the needle in a haystack” to uncover rare, novel causes of disease within the genome. Impeding the pace of discovery has been the existence of many small siloed datasets within individual research or clinical laboratory databases and/or disease-specific organizations, hoping for serendipitous occasions when two distant investigators happen to learn they have a rare phenotype in common and can “match” these cases to build evidence for causality. However, serendipity has never proven to be a reliable or scalable approach in science. As such, the Matchmaker Exchange (MME) was launched to provide a robust and systematic approach to rare disease gene discovery through the creation of a federated network connecting databases of genotypes and rare phenotypes using a common application programming interface (API). The core building blocks of the MME have been defined and assembled. Three MME services have now been connected through the API and are available for community use. Additional databases that support internal matching are anticipated to join the MME network as it continues to grow.
Here's a video presentation by Dr Kym Boycott, one of the authors.
Sunday, October 16, 2016
Two papers on repugnance and payments for body parts
Incentives and Ethics in the Economics of Body Parts
Nicola Lacetera
Efficiency-Morality Trade-Offs in Repugnant Transactions: A Choice Experiment
Julio J. Elias, Nicola Lacetera, Mario Macis
Friday, October 8, 2010
Organ donation legislation in California
On Tuesday, October 5, California Governor Arnold Schwarzenegger ceremonially signed new organ donor legislation. There are two new bills that make a variety of changes to policy for both live and deceased organ donation in California. Here is a summary.
SB 1395 makes two changes. First, it authorizes the creation of an:
"Altruistic Living Donor Registry" where individuals can state their willingness to be a live kidney donor. (The bill allows for the possibility of extending the registry to other organs and tissues in the future.) The living donor registry would make information about potential donors available to facilitate pairwise exchanges and donor chains. According to the bill: "(a) ... The donor registry shall be designed to promote and assist live kidney donations, including donor chains, paired exchanges, and nondirected donations. The registrar shall be responsible for developing methods to increase the number of donors who enroll in the registry. (b) The registrar shall make available to the federally designated organ procurement organizations (OPOs) and transplant centers in California information contained in the registry regarding potential altruistic living donors. This information shall be used to expedite a match between identified organ donors and potential recipients."
Second, SB 1395 changes how the department of motor vehicles asks people whether they would like to register to be an organ and tissue donor upon death (i.e. a deceased donor). Currently the DMV allows potential donors to opt in. The application for a new or renewal driver's license or ID card has space to indicate a willingness to join the registry. Starting July 1, 2011, the donor registration question will require an "active" or "mandated" choice. According to the bill, the application will now: "contain a space for the applicant to enroll in the Donate Life California Organ and Tissue Donor Registry. The application shall include check boxes for an applicant to mark either (A) Yes, add my name to the donor registry or (B) I do not wish to register at this time." In addition, the DMV: "shall inquire verbally of an applicant applying in person ... at a department office as to whether the applicant wishes to enroll in the Donate Life California Organ and Tissue Donor Registry."
In Governor Schwarzenegger's speech at the bill signing he called this change to mandated choice "the next best thing" to an opt out system, where individuals would be deceased organ donors by default. He said an opt out system had been suggested to him by Steve Jobs, who recently received a liver transplant and was also in attendance at the bill signing, but that an opt-out system was not plausible due to constitutional concerns. In the Governor's words: "And we have to give [Steve Jobs] a lot of credit, because he came back, apparently from Europe or from somewhere where he called me and he said that, you know, in Europe, in Spain, they have no waiting list because you can only opt out; that if you don’t opt out then you are automatically on a donor list. So we tried to copy the same thing and we talked about that seven months ago. But our Constitution in the United States is different than the Spanish Constitution, so we could not legally do that. So we did the next best thing."
Another bill generated protections for employees who want to be living organ donors or bone marrow donors. SB 1304 requires private employers to provide paid leave for their employees who are organ donors (up to 30 days) or bone marrow donors (up to 5 days) and prevents private employers from blocking such donations by its employees or punishing them for donating. State employees already had this paid leave.
Saturday, May 12, 2012
Compensation for bone marrow donors, continued
Saturday, November 11, 2017
Alabama adopts a paid leave program for organ donations
Alabama adopts a paid leave program for organ donations
"Under a new state provision, a permanent employee with at least one year of state service may be granted living donor leave, with pay, for donating an organ or bone marrow.
...
"Based on physician orders, the employer may receive up to 30 days to donate an organ and up to seven days to donate bone marrow. The employee does not have to exhaust his or her leave accruals for the procedures."
Tuesday, April 25, 2017
Organ transplantation in Iran
I'm not sure where the claim in the first sentence of 50,000 organ transplant "surgeries" comes from, but the rest of the article (which seems to talk about a total closer to 5,000 transplants) is an interesting view of the situation in Iran.
"Over 50,000 organ transplant surgeries were conducted during the last fiscal year that ended on March 20.
Thursday, February 9, 2017
Ethicists on compensation for blood stem cells (aka bone marrow aka hematopoietic cells) donors
The site is full of interesting related links.
Here's the site's front page:
**************
Here's a link to Hemeos, a startup service for matching stem cell donors to patients, which plans to compensate donors.
Sunday, May 20, 2012
NY Times debate: Is Prostitution Safer when It's Legal?
DEBATERS
Labor Laws, Not Criminal Laws, Are the Solution
CAROL LEIGH, BAY AREA SEX WORKERS ADVOCACY NETWORKLegality Leads to More Trafficking
RACHEL LLOYD, AUTHOR, "GIRLS LIKE US"Criminalize Only the Buying of Sex
MAX WALTMAN, UNIVERSITY OF STOCKHOLMIgnore the Stigma and Focus on the Need
MARTHA C. NUSSBAUM, UNIVERSITY OF CHICAGONevada’s Legal Brothels Make Workers Feel Safer
BARBARA G. BRENTS, UNIVERSITY OF NEVADA, LAS VEGASLegality Brings Protection and Better Care
CHIKA UNIGWE, AUTHOR, "ON BLACK SISTERS STREET"Such Oppression Can Never Be Safe
NORMA RAMOS, COALITION AGAINST TRAFFICKING IN WOMEN
INTRODUCTION
Monday, June 14, 2021
Repugnance to high incentives, by Robert Stüber
Here's a paper that seeks to understand why some transactions are permitted when only low incentives are offered, but banned when high incentives are offered. (Donation of human eggs is one example; high payments to participate in experiments is another...)
WHY HIGH INCENTIVES CAUSE REPUGNANCE: A FRAMED FIELD EXPERIMENT* by Robert Stüber
WZB Berlin March 2021
Abstract: A key feature of markets for repugnant transactions is that certain transactions seem to raise moral concerns only when they involve high monetary incentives. Using a framed field experiment with a representative sample, I show that these preferences exist, and I investigate why people display it. Participants can permit or prevent a third party from being financially compensated for registering as a stem cell and bone marrow donor. I find that a substantial fraction of individuals permit a low payment but prevent high monetary incentives. With the help of experimental treatment variation, I show that their preference to prevent high incentive offers is caused by the desire to protect individuals with high reservation prices. Evidence from a survey experiment with ethic committees emphasizes the practical importance of this finding. These results imply that shortages in the supply of controversial goods are unlikely to be solvable by providing higher incentives.
********
Here's a short video presentation of (an early version of) the paper by Dr Stüber. I understand that he will be moving from the WZP to NYU Abu Dhabi in September.
Tuesday, May 22, 2012
Public attitudes on compensation for donors
Poll: Americans Show Support For Compensation Of Organ Donors
"Federal law bans payments for organs. But given the need, we wondered what Americans thought about compensation for three kinds of donations that can be made while people are alive: kidneys, bone marrow and a portion of liver big enough to help someone whose liver is failing.
"So we asked 3,000 adults across the country as part of the NPR-Thomson Reuters Health Poll, and here's what they told us.
"If compensation took the form of credits for health care needs, about 60 percent of Americans would support it. Tax credits and tuition reimbursement were viewed favorably by 46 percent and 42 percent, respectively. Cash for organs was seen as OK by 41 percent of respondents.
"Among people who said some form of compensation was acceptable, 72 percent said it should come from health insurers, followed by private charities at 62 percent and the federal government at 44 percent.
"For all forms of compensation, rates of support tended to fall among older respondents.
"There's been longstanding resistance to compensating donors financially in this country. There are concerns about exploitation and also worries that even small amounts of compensation would undercut a system that depends on altruism."
HT: Steve Leider (and see Leider, Stephen and Alvin E. Roth, “Kidneys for sale: Who disapproves, and why?” American Journal of Transplantation, 10 (May), 2010, 1221-1227.)
Friday, December 31, 2010
Top 2010 stories about repugnant transactions (and all time top repugnant transactions)
Top 5 in 2010
- Same sex marriage
- Don’t ask, don’t tell in military..
- In-vitro fertilization (Nobel prize in 2010)
- Other reproduction related transactions: surrogacy, eggs
- Body parts for transplantation—compensation for donors (Kidneys, bone marrow, deceased donation…)
- Assisted suicide
- Marijuana (in CA…and lots of crime in Mexico) or Finance(? E.g. securitized mortgages…)
Top 5 of all time
- Sex (outside of marriage, same sex marriage, pornography prostitution…)
- Servitude: Slavery and serfdom and indentured servitude, women’s (lack of) rights (wasn’t so repugnant, now very much so)
- Worship (Inquisition, expulsions, heresy, religious wars)
- Interest on loans (was repugnant, no longer so much)
- Alcohol and mind-altering and addictive drugs (makes the list because of all the associated crime)
Friday, May 24, 2013
Economic rewards to motivate blood donations, by Lacetera, Macis and Slonim
"The position and guidelines of the World Health Organization (WHO) and several national blood collection agencies for nearly 40 years have been based on the view that offering economic incentives to blood donors is detrimental to the quantity and safety of the blood supply (1). The guidelines suggest that blood should be obtained from unpaid volunteers only (2). However, whether economic incentives positively or negatively affect blood donations (and other prosocial activities) has remained the subject of debate since the positions were established (2–8).
"Evidence consistent with the WHO position came originally from uncontrolled studies using nonrandom samples and, subsequently, from surveys and laboratory studies indicating that economic incentives can “crowd out” (decrease) intrinsic motivations to donate and can attract “worse” donors (9). This evidence arguably affected policies, such as bans on compensation for blood and organ donations in many countries.
...
"With a few early exceptions based on small, nonrepresentative samples (12), field trial evidence on how economic incentives affect blood donations has been absent. But field-based evidence from large, representative samples has recently emerged. The results are clear and, on important questions, opposite to the uncontrolled studies, surveys, and laboratory evidence preceding them."
...
"Conclusion
"In light of the recent evidence, it is time to re-examine policy guidelines for increasing and smoothing blood supply, including whether incentives can play a role. There are efforts under way from different parts of society toward using rewards to increase donations. The U.S. 9th Circuit Court of Appeals' 2012 ruling legalizing compensation for bone marrow donations through apheresis was initiated by private individuals (32). A company prompted a 2010 European Court of Justice ruling that allowed importation of blood products obtained from compensated donors (33). Researchers and clinicians have noted that some WHO guidelines (e.g., emphasis on exclusive use of nonremunerated donors and centralizing blood collection organizations) are unintentionally adversely affecting blood collection in sub-Saharan Africa (34).
"In addition to economic incentives, policy-makers should consider nonpecuniary rewards (e.g., symbolic and with social recognition) and various appeals. Debates on ethical issues around giving rewards for donations (35) should be encouraged. But there should be little debate that the most relevant empirical evidence shows positive effects of offering economic rewards on donations."