Showing posts with label incentives. Show all posts
Showing posts with label incentives. Show all posts

Thursday, November 28, 2019

Regulations gone awry -- an example from transplantation

A general lesson of market design is that participants have big strategy sets, so any given set of rules can have unanticipated undesirable consequences.  Here's an example from transplantation. Transplant centers are regulated in part based on their one-year survival rate.

Here's a story from the BMJ:

US hospital is accused of keeping vegetative patient alive to boost its transplant survival rate

"Federal agents are investigating a New Jersey hospital accused of keeping a patient with catastrophic brain damage alive for a year and barely consulting his family, in order to keep its one year transplantation survival rate from falling to a level where the programme’s Medicare certification might be withdrawn.

"The Centers for Medicare and Medicaid Services, which has its own law enforcement agency, will lead the investigation into Newark Beth Israel Medical Center. The hospital has launched its own internal probe.
...
"Newark Beth Israel’s heart transplantation programme is among the top 20 in the country by volume. A banner on the hospital’s facade says, “1000 hearts transplanted. Countless lives touched.”

"But in 2018, its one year survival rate fell significantly below the 91% national average. Young’s death would bring the average down to 81%, which staff feared would trigger sanctions from the public payer."

HT: Alex Chan

Wednesday, November 20, 2019

NYC school choice: long lines for high school tours (and some confusion about first choices)

The high school choice process in New York City uses an algorithm that makes it safe for families to list high schools in their order of preference over them.  But forming well-informed preferences is no easy task.

The NY Times has a story about long lines forming for tours of a desirable public high school:

Why White Parents Were at the Front of the Line for the School Tour
The high stakes of high school admissions in New York — and the lengths some go to get any small advantage.  By Eliza Shapiro

"Parents who pay $200 for a newsletter compiled by a local admissions consultant know that they should arrive hours ahead of the scheduled start time for school tours.

"On a recent Tuesday, there were about a hundred mostly white parents queued up at 2:30 p.m. in the spitting rain outside of Beacon High School, some toting snacks and even a few folding chairs for the long wait. The doors of the highly selective, extremely popular school would not open for another two hours for the tour.

"Parents and students who arrived at the actual start time were in for a surprise. The line of several thousand people had wrapped around itself, stretching for three midtown Manhattan blocks.
...
"Many New Yorkers cannot leave work in the middle of the afternoon, and some students surely did not know that the open house — or even the school — existed in the first place."
**********

The story goes on to talk about the matching system for high schools, which uses a deferred acceptance algorithm.  Parag Pathak points out to me that one paragraph contains a sentence that is easy to interpret incorrectly:

"Beacon, unlike Stuyvesant, does not have an admissions test. But to win a spot, students must have high standardized test scores and grades, along with a strong portfolio of middle school work and admissions essays. Students are much less likely to be accepted if they do not list Beacon as their top choice." (emphasis added)

Parag writes about this line: "while factually correct, the statement creates a misleading impression: a student is only less likely to get Beacon if they didn't list it as their top choice in the case that they were assigned their first choice school instead.  And most people who apply to Beacon list it first because it's their top choice. "

The manner in which the deferred acceptance algorithm (with students proposing) makes it safe for families to state their true preferences can be summarized this way: If you list Beacon as your second choice, and don't get your first choice, then your chance of admission to Beacon is the same as if you had listed it as your first choice.

Of course, even with that guarantee, a family's choice may not be simple if they would have liked to rank order 15 schools, and are only allowed to list 12. Then they have to consider whether, if they are rejected by their first choice, they are likely to be accepted by Beacon, or whether rejection from their first choice is a signal that they might not be competitive at Beacon either. (In which case, listing Beacon as first choice wouldn't have helped...)

See my recent post:

Thursday, November 14, 2019

Tuesday, October 8, 2019

Transplantation rates for patients in non-profit versus for-profit dialysis centers

From JAMA,September 10, 2019  Volume 322, Number 10:
J::AMA
September 10, 2019 Volume 322, Number 10Association Between Dialysis Facility Ownership and Accessto Kidney Transplantation

Jennifer C. Gander, PhD; Xingyu Zhang, PhD; Katherine Ross, MPH; Adam S. Wilk, PhD; Laura McPherson, MPH; Teri Browne, PhD;Stephen O. Pastan, MD; Elizabeth Walker, MS; Zhensheng Wang, PhD; Rachel E. Patzer, PhD, MPH

"MAIN OUTCOMES AND MEASURES: Access to kidney transplantation was defined as time from initiation of dialysis to placement on the deceased donor kidney transplantation waiting list,receipt of a living donor kidney transplant, or receipt of a deceased donor kidney transplant.Cumulative incidence differences and multivariable Cox models assessed the associationbetween dialysis facility ownership and each outcome.
RESULTS: Among 1 478 564 patients, the median age was 66 years (interquartile range, 55-76years), with 55.3% male, and 28.1% non-Hispanic black patients. Eighty-seven percent ofpatients received care at a for-profit dialysis facility. A total of 109 030 patients (7.4%)received care at 435 nonprofit small chain facilities; 78 287 (5.3%) at 324 nonprofitindependent facilities; 483 988 (32.7%) at 2239 facilities of large for-profit chain 1; 482 689(32.6%) at 2082 facilities of large for-profit chain 2; 225 890 (15.3%) at 997 for-profit smallchain facilities; and 98 680 (6.7%) at 434 for-profit independent facilities. During the studyperiod, 121 680 patients (8.2%) were placed on the deceased donor waiting list, 23 762 (1.6%)received a living donor kidney transplant, and 49 290 (3.3%) received a deceased donorkidney transplant. For-profit facilities had lower 5-year cumulative incidence differences foreach outcome vs nonprofit facilities (deceased donor waiting list: −13.2% [95% CI, −13.4% to−13.0%]; receipt of a living donor kidney transplant: −2.3% [95% CI, −2.4% to −2.3%]; andreceipt of a deceased donor kidney transplant: −4.3% [95% CI, −4.4% to −4.2%]). AdjustedCox analyses showed lower relative rates for each outcome among patients treated at allfor-profit vs all nonprofit dialysis facilities: deceased donor waiting list (hazard ratio [HR], 0.36[95% CI, 0.35 to 0.36]); receipt of a living donor kidney transplant (HR, 0.52 [95% CI, 0.51 to0.54]); and receipt of a deceased donor kidney transplant (HR, 0.44 [95% CI, 0.44 to 0.45]).
CONCLUSIONS AND RELEVANCE: Among US patients with end-stage kidney disease, receiving dialysis at for-profit facilities compared with nonprofit facilities was associated with a lower likelihood of accessing kidney transplantation. Further research is needed to understand the mechanisms behind this association.

Here are the figures. "For-profit large chains" seem to give the slowest access to being put on the transplant waiting list, receiving a living donation, or receiving a deceased donation.



HT: Irene Wapnir

Friday, August 16, 2019

Waitlists in NYC school choice--early reflections on yesterday's initial announcements

Yesterday the New York City Department of Education announced a change in the school choice assignment process--I gather that after one round of deferred acceptance, they will do something else, involving interim assignments  and wait lists.  (The original design included a subsequent round of deferred acceptance, after disseminating to unmatched students a list of schools with vacancies, and eliciting new preference lists for this second round.)
The details of the new plan for the second round aren't yet clear (at least to me).

Here's the press release from the city:

Mayor de Blasio, Chancellor Carranza Announce Easier and More Transparent Middle and High School Admissions Process
August 15, 2019
Families will now have one form and one deadline for middle and high school admissions

"“We are changing the middle and high school application processes so families don’t have to go through the gauntlet just to get a placement. There will be one application round and one deadline to make everyone’s lives easier.”
“We’ve heard from families and educators that they want a simpler, more transparent, and more accessible system of school choice, and today we’re taking a step forward,” said Schools Chancellor Richard A. Carranza. “This common-sense change will make a real difference for families across the five boroughs, and improve our middle and high school choice process for years to come.”
The DOE is eliminating the second application rounds for middle and high school. The main round application process and timeline will remain the same, with middle and high school applications opening in October with a December deadline. Students will receive their offer in March. Families can still appeal for travel, safety, or medical hardships; if families have any hardship, they will be able to access in-person support at Family Welcome Centers, rather than wait to participate in a second process. The waitlists will open after offers are released and will be a simpler, clearer process for families, increasing:
  • Transparency:  By knowing their waitlist position, families have a better understanding of their chances of getting into a preferred school option in the event that seats become available.
  • Ease: This is a shorter process that requires less paperwork. Rather than having to complete a second application and wait weeks—often into May or June—for a second decision or offer, families will complete one process, receive one offer, and receive any additional offers based on waitlist position.
  • Consistency:  Families will now have one admissions system at all grade levels, with the changes to the middle and high school process making it more similar to the elementary school admissions process. Currently the elementary school process has one round, and the middle and high school processes have two rounds with different names; now, families will not need to learn a different process each time a child applies to a new school—allowing them to focus on school options and not process."
************
From the WSJ:

New York City Introduces Wait Lists for Students Unhappy With School Placements
City’s complex school-choice system, in which students hope to be assigned to a top pick, has long been daunting for many families
By Leslie Brody

"In recent years, applicants who didn’t like their middle school assignments—given in spring for entry the next September—would have to go through an appeals process. High school applicants who didn’t like their offers would have to try a second round of applications and then appeal if need be.

"Under the new Department of Education system for fall 2020, students will be placed on wait lists for each school listed higher on their applications than the schools they were admitted to. They will be informed of their positions on wait lists and may be offered seats if they open up."

*******************
I got some emails about this. Here's my reply to a reporter...

"at this point I’m only an observer of NYC schools from a distance—I haven’t been involved in advising them for over a decade, and even then I worked only on the high school match, not anything involving middle schools.

So I don’t know anything about the current plans besides what I’ve read today ...

So I don’t have comments so much as questions.


  1. How is the NYCDOE going to handle the timing of moving waitlists?  Many vacancies don’t become visible until just before (or just after) the official start of school, which means that there could be some complications right around that time, for families and schools.
  2. How will students on multiple waitlists be dealt with?  Suppose a student waitlisted at multiple schools is admitted off one of them in the summer—if he or she accepts that new assignment, do his/her other waitlist positions remain?  
    1. (If other waitlists have to be given up, this could be a complicated decision whether to accept a somewhat preferred school, or wait for an even more preferred one…  If other waitlist positions can be maintained, then the process may move slowly, as some students accept for one waitlisted position, and then a better one when it becomes available, and maybe another…)
  3. How long will a student have to consider whether to accept a given waitlist position?


As with many questions of market design, the devil is in the details…"

and I added this in replies to followup emails asking for my thoughts on waitlists:

"I’ve always been cautious about waitlists, because some of the questions I asked you just don’t have good answers.  There’s a tension between wanting waitlists to move early and fast—to make planning easy for families and schools, and avoid disruption of the first week(s) of school, and wanting to give students the best chance at the schools they like best…"

"my colleagues and I never recommended waitlists to nyc, back at the turn of the century.:)
We thought it was important to reduce the number of “unmatched” students who had to be assigned to a school over which they  hadn’t had an opportunity to express preferences. This is why we had a second stage of the matching algorithm, in which lists of schools with still available places were disseminated to students unmatched in the first round, so that they could express preferences over these.

Another question about the new system is, how will such students now be assigned?  E.g. they might be assigned to the closest school to their home that has unfilled places.  In what order?  i.e. after some students are assigned this way, some schools will no longer have unfilled places, and students will have to be assigned to other schools.  The things I read today didn’t address that issue, but I gather that these interim assignments of unmatched students, which will turn out to be final assignments for students whose waitlists don’t move enough, will be made without having the students express preferences.

Another question about the waitlists: how will they be ordered?  According to the school priority/preferences that were used in the first round of matching?  Or perhaps unmatched students will be given preference? (that might sound attractive but I think it would be a bad idea, because it might make it seem desirable to be unmatched after the first round, which would interfere with eliciting student preferences altogether….)

My point is not to try to guess what design decisions have been made, but rather that there are lots of important decisions that have to be made to have a working system, and the initial announcements and news reports don’t reveal these. And they will have consequences.  So I hope that the system has been carefully designed."

Wednesday, August 7, 2019

Large strategy sets: college financial aid, and automatic weapons

One of the big lessons of market design is that participants have big strategy sets, so that many kinds of rules can be bent without being broken. That is, there are lots of unanticipated behaviors that may be undesirable, but it's hard to write rules that cover all of them. (It's not only contracts that are incomplete...)

Two examples in the recent news:

First, from ProPublica Illinois:
Parents Are Giving Up Custody of Their Kids to Get Need-Based College Financial Aid
First, parents turn over guardianship of their teenagers to a friend or relative. Then the student declares financial independence to qualify for tuition aid and scholarships.
by Jodi S. Cohen and Melissa Sanchez July 29

and
U.S. Department of Education Wants to Stop “Student Aid Fraud Scheme” Where Parents Give Up Custody Through Dubious Guardianships
One day after our reporting, the department’s inspector general said it wants to close financial aid loopholes.
by Jodi S. Cohen, Duaa Eldeib and Melissa Sanchez July 30
*******

Second (with pictures), pointed out to me by Jacob Leshno:

When Lawmakers Try to Ban Assault Weapons, Gunmakers Adapt
By Jeremy White

Tuesday, February 19, 2019

Payments for kidney disease in the U.S.

Medpage Today has the story:

Kidney Disease Payment System Draws Medicare Scrutiny
'We do not think the state of kidney disease care is acceptable'

"Medicare needs to change the way it pays for kidney disease treatment in order to get better results, Adam Boehler, director of the Center for Medicare & Medicaid Innovation, said here.

"We do not think the state of kidney care is acceptable," Boehler said Wednesday at the annual meeting of the Healthcare Information and Management Systems Society. "Right now, we're at a place where 10% of patients in Medicare [with kidney disease] are seen at home, while you have Hong Kong, with a 70% rate. That's not OK. The level of transplants is not OK."

"What happens is that end-stage renal disease (ESRD) is siphoned out and [effort is] focused there, instead of viewing the whole spectrum, instead of thinking about chronic kidney disease before ranging from diagnosing it in the first place, to integration of later-stage chronic kidney disease, to ESRD," he said. "Because what you really want is the prevention of ESRD from developing," he said. "If it develops, you want [it] to be transplant wherever possible; if not, [treatment at] home wherever possible, and it should be a last resort that people go to a dialysis center."

...

"Boehler said he wasn't trying to demonize dialysis centers. "It's our fault; we set the incentives," he said, referring to Medicare. "You need to change those incentives. If we want people to do what's best for patients, if we want them to lower costs and improve quality for patients, they need to make money for doing that -- we'll look specialty by specialty to set it up like that."

"Medicare spends about $120 billion a year on kidney care, Boehler noted. "The first thing you may think about in ESRD is dialysis centers ... but that is not the majority of spend. The majority of spend is in other places -- hospitals, complications arising from them, et cetera. That doesn't mean we have to cut the spend there; it means you have to change around the way people make money." Right now, he said, for the dialysis centers, "if somebody gets a transplant, that's a lost customer."

Tuesday, November 13, 2018

Welfare of sophisticated versus naive players revisited, by Babaioff, Gonczarowski, and Romm

Here's a new paper with a nuanced view of how well sophisticated players may do in a non-strategy-proof mechanism:

Playing on a level field: Sincere and sophisticated players in the Boston mechanism with a coarse priority structure
Moshe Babaioff, Yannai A. Gonczarowski, Assaf Romm∗
October 15, 2018

Abstract: Who gains and who loses from a manipulable school choice mechanism? We examine this question with a focus on the outcomes for sincere and sophisticated students,and present results concerning their absolute and relative gains under the manipulable Boston Mechanism (BM) as compared with the strategy-proof Deferred Acceptance (DA). The absolute gain of a student of a certain type is the difference between her expected utility under (an equilibrium of) BM and her utility under (the dominant strategy quilibrium of) DA. Holding everything else constant, one type of a player has relative gain with respect to another type if her absolute gain is higher. Prior theoretical works presented inconclusive results regarding the absolute gains of both types of students, and predicted (or assumed) positive relative gains for sophisticated types compared to sincere types. The empirical evidence is also mixed, with different markets exhibiting very different behaviors. We extend the previous results and explain the inconsistent empirical findings using a large random market approach. We provide robust and generic results of the “anything goes” variety for markets with a coarse priority structure. That is, in such markets there are many sincere and sophisticated students who prefer BM to DA (positive absolute gain), and vice versa (negative absolute gain). Furthermore, some populations may even get a relative gain from being sincere (and being perceived as such). We conclude by studying market forces that can influence the choice between the two mechanisms.

Saturday, November 10, 2018

Obvious manipulations by Pete Troyan and Thayer Morrill

Here's a paper motivated by the fact that (obviously:) there are going to be many more mechanisms that aren't obviously manipulable than there are mechanisms that are obviously strategy proof, or even strategy proof...

Obvious Manipulations
Peter Troyan, Thayer Morrill∗ (*in random order)
October 3, 2018

Abstract: A mechanism is strategy-proof if agents can never profitably manipulate, in any state of the world; however, not all non-strategy-proof
mechanisms are equally easy to manipulate - some are more “obviously”
manipulable than others. We propose a formal definition of an obvious
manipulation and argue that it may be advantageous for designers to
tolerate some manipulations, so long as they are non-obvious. By doing
so, improvements can be achieved on other key dimensions, such as
efficiency and fairness, without significantly compromising incentives.
We classify common non-strategy-proof mechanisms as either obviously
manipulable (OM) or not obviously manipulable (NOM), and show that
this distinction is both tractable and in-line with empirical realities
regarding the success of manipulable mechanisms in practical market
design settings

"Intuitively, a manipulation ...is classified as “obvious” if it either makes
the agent strictly better off in the worst case ...or it makes the agent strictly better off in the best case..."

Thursday, July 19, 2018

Manipulation by doctors of the Organ Allocation System Waitlist Priority

You will be shocked to learn that doctors and transplant centers respond to incentives in their effort to get scarce organ transplants for their own patients...

Here's a recent OPTN/UNOS white paper on the subject, concerning the waitlist for organs (such as hearts) for which physician decisions can influence patients' position on the waitlist.

Manipulation of the Organ Allocation System Waitlist Priority through the Escalation of Medical Therapies

"This white paper provides an ethical analysis of physicians’ practices of escalating care to waitlisted transplant candidates in order to increase their priority in the allocation system. Many in the transplant community perceive, as expressed explicitly in the medical literature23, that this practice of unnecessary escalation of care is widespread, and recognize that physicians may feel compelled to similarly manipulate the waitlist priority system so that their candidates are not disadvantaged as a result of the practices of others.

"For example, in heart transplantation, priority status can be influenced by the degree of therapeutic intervention applied to the transplant candidate, based on the assumption that therapeutic measures are a reliable indicator of disease severity.4 An unintended consequence of this approach is that a physician can raise the priority status of a patient by instituting more advanced therapeutic measures even in the absence of true medical necessity, a tactic some informally refer to as “gaming.”

"Due to the organ shortage, the transplant waitlist “is functionally a zero-sum rationing process.”5 Shortening wait times for some directly increases wait times for others. Thus, the practice of instituting more advanced therapies to shorten an individual’s wait time has no beneficial effect on wait times for the patient population in the aggregate. However, manipulating care to achieve a higher candidate priority can generate complications in candidates receiving such care while also jeopardizing public trust in the organ allocation system, which in turn, could reduce organ donation rates.

"OPTN/UNOS leadership requested an ethical analysis regarding the manipulation of the organ allocation system, particularly as it pertains to medically unnecessary escalation of interventions that are instituted for the sole purpose of increasing a candidate’s waitlist priority. The OPTNhas not previously commented on this issue."
...

"During the mid-late 1990s, three transplant hospitals in Chicago, IL were alleged by federal and state authorities to have falsely reported patients as critically ill in order to house them in the intensive care unit for the purpose of moving them to the top of the liver transplant waitlist.20 The hospitals denied any wrongdoing, but did receive financial penalties. These incidents generated questions about the integrity and fairness of the liver allocation system based on the alleged events.21,22

"In the last five years, prominent editorials described the widespread use of medical interventions that are not thought to be medically indicated in routine practice, but allow for patients to receive higher waitlist priority.23,24 This includes increased utilization of pulmonary artery (PA) catheters with continuous inotropes for the purpose of increasing the priority status on the waitlist of a patient with heart failure.25 While there are situations in which PA catheter use is appropriate, this intervention is associated with excessive adverse complications, which typically prohibits its routine use. When use of PA catheters was aligned with allocation priority, increasing use of PA catheters quickly followed.26 Further, vascular complications that preclude further catheterization have evolved to become a major justification for Status 1A exceptions, which are presumed to be related to overuse of PA catheters.27,28

"Increasingly, heart transplant candidates are being listed as Status 1A (the highest priority), which is largely based on the intensity and risk of the intervention used to treat the patient. This category was originally intended for potential transplant candidates expected to survive less than one week. Now, it’s not uncommon for Status 1A patients to have longer waitlist survival, and they may wait 6-12 months ."
...
"Multiple stakeholders stand to gain from manipulating the allocation system, including the candidate and the transplant hospital."

Tuesday, June 19, 2018

Why high incentives might require muscular informed consent (Ambuehl, Ockenfels and Stewart)

Here's a new paper (or at least just recently on the web) showing that subjects who are enticed by high payments might be disproportionately those who have difficulty gathering information about the risks...i.e.. these potential participants respond more to high payoffs than those who might have been able to gather information easily (and might have participated for a lower payment or been deterred even despite a high payment).

Attention and Selection Effects

CESifo Working Paper No. 7091 (Mai 2018)
Primary CESifo Category: [13] Behavioural Economics 
Abstract:
Who participates in transactions when information about the consequences must be learned? We show theoretically that decision makers for whom acquiring and processing information is more costly respond more strongly to changes in incentive payments for participating and decide to participate based on worse information. With higher payments, the pool of participants thus consists of a larger proportion of individuals who have a worse understanding of the consequences of their decision. We conduct a behavioral experiment that confirms these predictions, both for experimental variation in the costs of information acquisition and for various measures of information costs, including school grades and cognitive ability. These findings are relevant for any transaction combining a payment for participation with uncertain yet learnable consequences.

Sunday, June 17, 2018

Title IX reporting incentives and mis-incentives

The Atlantic has a story on a strange Title IX case (and a resulting lawsuit), with the suggestion that it might have to do with perverse legal and procedural incentives:

Mutually Nonconsensual Sex

Here's the critical paragraph:
"The event in précis, as summarized by Robby Soave of Reason magazine:
“Male and female student have a drunken hookup. He wakes up, terrified she's going to file a sexual misconduct complaint, so he goes to the Title IX office and beats her to the punch. She is found guilty and suspended.”

HT: MR

Saturday, June 9, 2018

Gaming the Affordable Care Act (ACA)

One of the big lessons of market design is that participants have big strategy sets. Here's a new paper that explores some of what that has implied about how the Affordable Care Act is gamed by some participants.

Take-Up, Drop-Out, and Spending in ACA Marketplaces

Rebecca DiamondMichael J. DicksteinTimothy McQuadePetra Persson

NBER Working Paper No. 24668
Issued in May 2018
NBER Program(s):Health CarePublic EconomicsIndustrial Organization 
The Affordable Care Act (ACA) established health insurance marketplaces where consumers can buy individual coverage. Leveraging novel credit card and bank account micro-data, we identify new enrollees in the California marketplace and measure their health spending and premium payments. Following enrollment, we observe dramatic spikes in individuals' health care consumption. We also document widespread attrition, with more than half of all new enrollees dropping coverage before the end of the plan year. Enrollees who drop out re-time health spending to the months of insurance coverage. This drop-out behavior generates a new type of adverse selection: insurers face high costs relative to the premiums collected when they enroll strategic consumers. We show that the pattern of attrition undermines market stability and can drive insurers to exit, even absent differences in enrollees' underlying health risks. Further, using data on plan price increases, we show that insurers largely shift the costs of attrition to non-drop-out enrollees, whose inertia generates low price sensitivity. Our results suggest that campaigns to improve use of social insurance may be more efficient when they jointly target take-up and attrition.

Tuesday, January 24, 2017

Lifesharers has shut down:

With a whimper rather than a bang (I just noticed it recently), the valiant, Quixotic attempt to introduce--via a private club--priority for deceased donation to those who were registered donors themselves, has ended.
(see my post from 2008: Tuesday, December 23, 2008 Lifesharers: organ donation as a club good rather than a public good

Here's the lifesharers final anouncment:

Monday, March 21, 2016

LifeSharers has shut down.

"If your durable power of attorney for healthcare mentions your agreement to donate your organs through LifeSharers, you should change it.

If you have told your family and/or your doctors that you want to donate your organs through LifeSharers, you should let them know that's no longer possible."
**************
It was an interesting but doomed attempt to do privately something very much like what has been done publicly in Israel -- here are my posts on priority donation in Israel.

Judd Kessler and I proposed a model which distinguished between the effective Israeli approach and the well-intentioned but inefficacious Lifesharers approach as follows. In Israel, those who register for donation gain priority for the already existing pool of deceased donors, while in Lifesharers the initial members only gain priority for each other. So, if there is even a small cost of joining, there is an equilibrium at which no one joins lifesharers, and indeed, unfortunately, it seems that Lifesharers never gained enough members to facilitate even a single transplant.

Contrast the difficulty of getting mutual donation going (with each death leading to only a very low probability of making a donation possible), with the easier task faced by the 19 Century Society for Mutual Autopsy 

Saturday, December 17, 2016

The politics (and incentives) of liver transplants

From the LA Times: California has long wait lists for liver transplants, but not for the reasons you think

"About 7,000 people get a liver transplant each year in the United States, while 17,000 remain on waiting lists at transplant centers. Who should get a lifesaving transplant has always been a complex calculation. But it has blown up into a vicious political struggle that played out most recently at a meeting of the organization governing the nation’s transplant network.

"The benefits of liver transplants are astounding. Patients just weeks from death can have their lives extended significantly, even indefinitely. Given the limited number of donor livers, in 2000 Congress established what’s called “the Final Rule” to guide the medical community in how to allocate them fairly. The Final Rule compels the transplant community to allocate donor organs based on best medical judgment, best use of the organs and avoidance of futile transplants. It also notes that a patient’s chance of getting a transplant should not be affected by where he or she lives.

"Balancing these various guidelines has always been tricky. But what has emerged — and is now the point of contention — is a marked geographic disparity in how sick a patient must be before rising to the top of a transplant list. For example, waiting lists at California transplant centers are significantly longer (and therefore patients in California get a lot sicker before possibly receiving transplants) compared with waiting lists in Oregon. That’s unfair to the Californians who need liver transplants, right?

"Acting on this assumption, the national board of the Organ Procurement and Transplantation Network / United Network for Organ Sharing, or OPTN/UNOS, proposed new boundaries for the nation’s transplant regions. The aim was to have regions with shorter, less-sick waiting lists share the limited supply of donor livers with regions that have longer, more-sick waiting lists. The new map was recently offered for public comment and a regional advisory vote.

"Eight of the 11 regions came out against it — because longer waitlists aren’t necessarily a sign of greater need.

The divide is deep. Antagonists have split into camps (“Liver Alliance” versus “Coalition for Organ Distribution Equity”), hired lobbyists and collected their congressional representatives. Given the uproar, it was not surprising that the OPTN/UNOS board of directors declined to vote on the controversial proposal at its national meeting in St. Louis last week. Nevertheleess, there’s a feeling of urgency that something must be done, so it’s entirely possible the board will soon enact the redistribution proposal — perhaps with minor modifications — despite present objections.
...
"Transplant waiting lists also get distorted by intense competition in populous regions where there are more liver transplant centers — a largely ignored issue. With money and prestige at stake, centers are motivated to perform more liver transplants. The simplest way to accomplish that is to put very ill patients on the transplant list, because when a donor organ becomes available, the center with the sickest listed patient in that region gets the organ.

Unfortunately, this encourages centers to list sicker patients over those who have the best chance of long, high-quality lives post-transplant.
...
"Rates of organ donation, by the way, do not explain the wait-list problem: California has some of the highest donation rates in the country, while New York persistently ranks at the bottom. Everyone agrees on the need to increase donations — but just redistributing livers will not significantly change the number of transplants or lives saved.

"Still, the disparity between the wait lists causes endless teeth-grinding in the transplant community.

"There is no question that wait lists are abhorrently long in some places, but OPTN/UNOS’ redistribution proposal misses the larger point: What is it about our transplant system that has created this situation? How can we make changes to keep the wait lists at more reasonable levels?

"Matters of healthcare access, while important, are beyond the control of OPTN/UNOS and the transplant community. Within grasp, however, is a simple solution: Lower the number of patients on transplant lists. Such a move would not affect the number of transplants (every available liver would still be transplanted), but it would reduce the delay and degree of illness for those on the wait lists. This is, of course, simple to say, but difficult to implement given how our current system incentivizes transplant centers to get as many patients on their lists as possible.

"To create a fairer balance between the haves and have-nots, though, both factions in the liver debate need to understand (and agree on) who the haves and have-nots actually are. Without consensus on that, we risk missing the big picture: increasing the health, happiness and well-being of more people with liver disease."

Dr. Willscott E. Naugler is an associate professor and medical director of liver transplantation at Oregon Health & Science University in Portland. He also serves as the Region 6 (Pacific Northwest) regional representative to the UNOS Liver and Intestine Committee."

Thursday, September 15, 2016

Sally Satel, on how she was lucky twice, and others shouldn't have to be

Sally Satel, the tireless fighter to make kidney transplants more accessible, writes in two recent articles about her good luck in receiving organs from friends, and about how providing greater incentives to donors might work...

This one is in Slate:

A College Tuition Payment for Your Spare Kidney? 
A new bill proposes an alternative way to compensate people for their organ donation. We should try it.
(The URL is as informative as the headline: http://www.slate.com/articles/health_and_science/medical_examiner/2016/09/the_current_kidney_donation_system_is_failing_us.html )

And this one is in Statnews:
 Vouchers and incentives can increase kidney donations and save lives

Saturday, August 13, 2016

Gaming the waiting list for a heart transplant

The heart transplant waiting list is game-able, since your place on the list depends on what treatment you are getting. So your doctor can "treat your priority" as well as treat your medical condition.  Here's the story from NPR:
Should Doctors Game The Transplant Wait List To Help Their Patients?
 July 24, MATTHEW MOVSESIAN

And here's an old (2013) editorial on the subject in The Journal of Heart and Lung Transplantation:
The urgent priority for transplantation is to trim the waiting list by Lynne Warner Stevenson:

"Current definitions of priority levels have been based both on medical rationale and the attempt to protect the system from being “gamed.” When the requirements for inotropic therapy for Status IB and pulmonary artery catheters for Status IA were adopted in the USA, it was with optimism that they would be used only when absolutely necessary to prevent imminent death, because continuous inotropic infusions and indwelling pulmonary artery catheters are inconvenient and costly and have been associated with serious complications. Although individual cases trigger heated controversy in regional committees, it is generally agreed that these therapies are being overused in patients awaiting transplantation.

If high priorities defined by therapies are the only route to access donor hearts, we face conflicted incentives as advocates for our patients. This is serious enough with incentives to inflate the description of severity of illness, but even more serious with incentive to impose interventions with complications, such as indwelling pulmonary artery catheters. One of the major conditions currently cited as justification for Status IA exceptions is vascular complications of indwelling catheters that preclude further catheterization. This complication on the list was virtually never seen before pulmonary artery catheters became an index of priority (although arrhythmia device leads have also added to the vascular complication rate).

The strength of inverse incentives in care of our waiting patients is indexed to the concern that they will die before a transplant, or will develop unnecessary risk such as from cachexia before they finally enter into transplant. The priority status will more truly reflect patient illness when the listing physicians have reasonable confidence that patients will receive a heart in a timely manner, a confidence eroded by the lengthening waiting times, which in turn reflect the anasarca of the waiting list."

HT: Marc Melcher

Monday, August 1, 2016

Monday, April 13, 2015

A problem for the NRMP that may be growing

I've had correspondence and conversations with a number of residency program directors, about a common problem that may interfere with how safe they feel about rank-ordering residency and fellowship applicants according to their true preferences.

I'll quote from some emails without identifying the senders.

"I oversee the xxx residency match ....

"There is a terrible game that is going on in some surgical fields, though.  Program directors feel that it is prestigious not to go down their lists very far.  A program director may boast to his/her Chair, "This year we only needed to go down to #6 on our list to fill our (3) positions."  This ambition to not go down far on a list, as evidence that a program is highly desirable, is often achieved by pressuring candidates in the following way, "If you want to come here, you really need to let us know," which translates to "tells us we are your #1 and then you will have a chance to match here."  These actual or implied quid pro quos are a shame and pervert the intent of the match and your good work.  I know the NRMP considers them illegal or at least poor practices, but they are common, unfortunately."

**********

"I work in xxx [non-surgical specialty], which is a specialty that is very competitive for the match.  Although the system that you helped develop should match applicants and residency programs based on the rankings that applicants and programs provide according to their independent preferences, some prestigious residency programs in xxx (and likely other specialties) are being evaluated by hospital presidents or other administrative officials by how far down the rank list they must go to fill their complement of residents.  This in turn has created an environment where some programs are ranking applicants according to the likelihood that the applicant will rank the program in the top slot rather than if they believe that the applicant is truly the best applicant for their program.  While I believe that each residency  program should be able to use whatever criteria they want to for ranking applicants, the problem is that some residency program directors or department chairs are contacting applicants or faculty at which the medical students train to find out if their program is at the top of the applicant’s rank list.  This puts the applicants in an awkward position and in my opinion likely biases the match result to hurt some applicants.

In an ideal world, such behavior by residency programs could be prevented by explaining that it violates the principles of the match.  However, I am afraid that this approach will be unlikely to remove the cause of this problem: pressure that some departments feel from administrators and hospital presidents."
************

Perhaps the community (directors and NRMP) could be persuaded that residency directors shouldn’t show their rank order lists to their deans and chairs?  

Saturday, January 10, 2015

Scott Kominers speaks about Strategy-Proofness, Investment Efficiency and Marginal Returns -- video

Here's a video of a recent lecture by Scott Kominers: Strategy-Proofness, Investment Efficiency and Marginal Returns

"In this presentation, Scott Duke Kominers noted that mechanism design tends to examine only the market clearing stage. The field treats human capital as a fixed or predetermined input, rather than a dynamic range of possibilities. His own model uncovers a relationship between three variables: strategy-proofness, investment efficiency, and marginal rewards."

Wednesday, October 8, 2014

Incentives in multi-hospital kidney exchange

Itai Ashlagi and I have a paper in the latest issue of Theoretical Economics:
Free riding and participation in large scale, multi-hospital kidney exchange
Volume 9Issue 3pages 817–863September 2014
Abstract: "As multi-hospital kidney exchange has grown, the set of players has grown from patients and surgeons to include hospitals. Hospitals can choose to enroll only their hard-to-match patient–donor pairs, while conducting easily arranged exchanges internally. This behavior has already been observed.

We show that as the population of hospitals and patients grows, the cost of making it individually rational for hospitals to participate fully becomes low in almost every large exchange pool (although the worst-case cost is very high), while the cost of failing to guarantee individual rationality is high—in lost transplants. We identify a mechanism that gives hospitals incentives to reveal all patient–donor pairs. We observe that if such a mechanism were to be implemented and hospitals enrolled all their pairs, the resulting patient pools would allow efficient matchings that could be implemented with two- and three-way exchanges."

The paper was actually written some time ago, and took a long time to publish partly because the phenomenon it identifies, the withholding of easy to match pairs by big transplant centers, was controversial among referees. It isn't controversial anymore: it's one of the clearest features of contemporary kidney exchange that the flow of incoming patients to multi-hospital kidney exchange is skewed towards the hardest to match patients. Hence the success of  potentially long, non-simultaneous extended altruistic donor chains (NEAD chains), which we've explored in other papers.