Friday, September 30, 2016

A von Neumann medal in the shape of a saddle point


It's a little hard to see, but the medal forms a saddle point: the intersection of the two lines is a maximum in the horizontal direction and a minimum in the vertical direction...  It had been a long time since I thought of equilibrium that way, but it is from von Neumann's first game theory paper, on two person zero sum games and the minimax theorem.

It is from my trip to Hungary in early September. You can read about it in Hungarian...

Nobel-díjas közgazdász, Alvin E. Roth kapta idén a Neumann János-díjat



Piaci megoldással osztaná el a migránsokat a Nobel-díjas közgazdász


Nobel-díjas közgazdász oldhatja meg a menekültproblémát

Hungarian radio: (interview in Hungarian voice-over)
A pénz sem old meg mindent - így látja a Nobel-díjas, InfoRádió / Czwick Dávid


Isten teremtette a búzát. És az árutőzsdét? (a newspaper interview in Hungarian)
Google translate: God created the wheat. And the commodities market?



Thursday, September 29, 2016

It looks like paying donors of bone marrow/ blood stem cells will remain illegal...

The long story of whether some forms of blood stem cell (marrow) donation may be compensated seems to be coming to an end, back where it began.  Here's the new HHS/HRSA regulation, saying that whether as marrow or in the blood stream, these are considered organs under the National Organ Transplant Act, so no valuable consideration can be given...

View EO 12866 MeetingsPrinter-Friendly Version     Download RIN Data in XML

HHS/HRSARIN: 0906-AB02Publication 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 AgendaAgenda 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:
ActionDateFR Cite
NPRM 10/02/2013 78 FR 60810   
NPRM Comment Period End 12/02/2013 
Final Rule 11/00/2016 
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

Wednesday, September 28, 2016

Is vote swapping related to vote selling the way kidney exchange is related to kidney sales? (a blog post by Scott Aaronson on vote swapping)

Here's a blog post from Scot Aaronson's blog "Shtetl Optimized". He points out that although vote trading is illegal, vote swapping seems not to be. (Apparently it's the money that matters, as in kidney exchange versus kidney sales...)

Here are the critical paragraphs in that connection from his post:
"On August 6, 2007, the Ninth Circuit Court of Appeals finally ruled on a case, Porter v. Bowen, stemming from the California attorney general’s shutdown of voteswap2000.com.  Their ruling, which is worth reading in full, was unequivocal.
Vote-swapping, it said, is protected by the First Amendment, which state election laws can’t supersede.  It is fundamentally different from buying or selling votes."

Here's the whole post, together with some interesting updates added later.

The Ninth Circuit ruled that vote-swapping is legal. Let’s use it to stop Trump.



"Updates: Commenter JT informs me that there’s already a vote-swapping site available: MakeMineCount.org.  (I particularly like their motto: “Everybody wins.  Except Trump.”)  I still think there’s a need for more sites, particularly ones that would interface with Facebook, but this is a great beginning.  I’ve signed up for it myself.
Also, Toby Ord, a philosopher I know at Oxford, points me to a neat academic paper he wrote that analyzes vote-swapping as an example of “moral trade,” and that mentions the Porter v. Bowendecision holding vote-swapping to be legal in the US."
***********

Here are two passages from the Ninth Circuit opinion that I found particularly relevant.
The first says that operating vote swapping sites might be protected political speech:

"On the merits, we hold that Jones violated Appellants’ First Amendment rights. The websites’ vote-swapping mechanisms as well as the communication and vote swaps they enabled were constitutionally protected. Although California certainly has valid interests in preventing election fraud and corruption, and perhaps in avoiding the subversion of the Electoral College, these interests did not justify the complete disabling of the vote-swapping mechanisms."

The second addresses the issue of "corruption":
"Corruption. Beginning with the State’s anticorruption interest, we reiterate that we construe this interest to encompass only the prevention of illicit financial transactions such as the buying of votes or the contribution of large sums of money to legislators in exchange for political support. See WRTL, 127 S. Ct. at 2676 (Scalia, J., concurring in part and concurring in the judgment); NCPAC, 470 U.S. at 497; Buckley, 424 U.S. at 26-27. So defined, this interest was not advanced by the threatened prosecution of the owners of voteswap2000.com and votexchange2000.com. The websites did not encourage the trading of votes for money, or indeed for anything other than other votes. Votexchange2000.com actually included a notation that “It is illegal to pay someone to vote on your behalf, or even get paid to vote yourself. Stay away from the money. Just vote” (emphasis in original). And there is no evidence in the record, nor has the Secretary argued, that any website users ever misused the voteswapping mechanisms by offering or accepting money for their votes. "



HT: Nicole Immorlica

Tuesday, September 27, 2016

National Living Organ Donor Assistance Center (NLDAC)

I've recently joined the advisory board of the National Living Organ Donor Assistance Center (NLDAC), which gives certain forms of financial assistance--mostly travel assistance--to living organ donors.  I expect to learn more about what they do, and can do, in the months to come.

Here's a page outlining how to apply for travel assistance.

And here's a paper describing its history and experience:
Development of the National Living Donor Assistance Center: reducing financial disincentives to living organ donation, by
Patricia H. Warren, RN, CPTC, Kimberly A. Gifford, MBA, Barry A. Hong, PhD, Robert M. Merion, MD, and Akinlolu O. Ojo, MD, PhD, MBA

Abstract: Over the years, the transplant community has worked to advance the care of living organ donors; however, barriers remain, including the nonmedical expenses incurred by living donors. A new center, funded by a grant from the Health Resources and Services Administration (HRSA), was established to operate a nationwide system to remove these financial disincentives. The HRSA grant was awarded to an academic institution and the daily operations are managed by a transplant professional society. Expenses are reimbursed prospectively for financially needy living donors. Combining the legislative authority and economic resources of the federal government, the research experience of an academic institution, and the management know-how of a professional society has proven to be successful. To date, the center has received 3918 applications submitted by 199 different transplant centers and receives about 80 applications per month. On average, a donor spends $2767 for their travel expenses to the transplant center. Of the 3918 applications that have been submitted, 1941 of those applicants (50%) have completed their donor surgery.


Monday, September 26, 2016

The effects of Israel's new organ transplantation law on family consent for deceased donation

Deceased donor organs are a scarce resource with the property that how they are allocated may influence their scarcity, by influencing the decisions of potential donors and their families.  Recent changes in Israeli law give us a window on this...
Incentivizing Authorization for Deceased Organ Donation With Organ Allocation Priority: The First 5 Years
by A. Stoler, J. B. Kessler, T. Ashkenazi, A. E. Roth, J. Lavee

American Journal of Transplantation, Volume 16, Issue 9, September 2016
Pages 2639–2645

Abstract

The allocation system of donor organs for transplantation may affect their scarcity. In 2008, Israel's Parliament passed the Organ Transplantation Law, which grants priority on waiting lists for transplants to candidates who are first-degree relatives of deceased organ donors or who previously registered as organ donors themselves. Several public campaigns have advertised the existence of the law since November 2010. We evaluated the effect of the law using all deceased donation requests made in Israel during the period 1998–2015. We use logistic regression to compare the authorization rates of the donors’ next of kin in the periods before (1998–2010) and after (2011–2015) the public was made aware of the law. The authorization rate for donation in the period after awareness was substantially higher (55.1% vs. 45.0%, odds ratio [OR] 1.43, p = 0.0003) and reached an all-time high rate of 60.2% in 2015. This increase was mainly due to an increase in the authorization rate of next of kin of unregistered donors (51.1% vs. 42.2%). We also found that the likelihood of next-of-kin authorization for donation was approximately twice as high when the deceased relative was a registered donor rather than unregistered (89.4% vs. 44.6%, OR 14.27, p < 0.0001). We concluded that the priority law is associated with an increased authorization rate for organ donation.

Sunday, September 25, 2016

Notes from China 2: Lanzhou

I spoke in Lanzhou on Thursday, in Gansu Province, as part of a festival promoting the revival of the Silk Road as a market for international trade. The sponsors were Time Weekly, Readers Group (a wide circulation, Readers Digest kind of publisher...www.duzhe.com), and the provincial government.

Here's an interview published in China Daily:

诺贝尔经济学奖得主埃尔文·罗斯:中国市场必须由中国经济学家设计
作者:孟肖 来源:时代周刊 2016-09-20
Google translate renders the headline this way: Nobel laureate Erwin Ross: Chinese market must be designed by a Chinese economist
Author: Meng Xiao Source: Times 2016-09-20 
Kwong Sunrise Photo--Al Roth 



The provincial museum is well worth a visit.


And the Yellow River has some beautiful bridges: I took these photos from a riverboat at night.



I recommend the Lanzhou beef noodles, which I had for lunch  The banquet food in Lanzhou is also easy for Americans--fish, lamb, beef and Yak were prominent. (Yak is a kosher animal, by the way...). And toasting goes on throughout, not just in wine but in 100 proof rice liquor...



And in case you were wondering how to spell Erwin Ross in Chinese, I think this is it:

Notes from China 1: Changsha

The first of two stops on my recent trip to China was in Changsha, in Hunan province.  I spoke about market design, following the publication of Who Gets What and Why in Chinese (the Chinese title was changed to The Sharing Economy, but the subtitle was still The New Economic of Matchmaking and Market Design).

Here's a picture I took of the stage, before the talk began:



Here are links to some press coverage, including a visit to ResGreen corporation, a sponsor:

Full coverage

诺奖得主埃尔文-罗斯长沙谈共享经济:核心在于稳定匹配

星辰在线 - ‎Sep 20, 2016‎
今日,诺贝尔经济学奖获得者埃尔文-罗斯(Alvin E. Roth)携最新的研究成果来到湖南长沙,走进了以绿之韵集团为代表的中国本土企业,与中国的商业巨鳄、学者专家共同探讨共享经济时代下的市场设计话题。

诺贝尔经济学奖得主埃尔文·罗斯:中国市场必须由中国经济学家设计

新浪网 - ‎Sep 19, 2016‎
罗斯(Alvin E. Roth),罗斯因在博弈论、市场设计和实验经济学领域作出的显著贡献,而于2012年获得诺贝尔经济学奖,目前罗斯在哈佛商学院担任经济及工商管理学教授,他多次访问中国,对目前中国经济的 ...

诺奖得主罗斯走进绿之韵谈共享经济:核心在于稳定匹配

湖南在线 - ‎Sep 21, 2016‎
埃尔文·罗斯(Alvin E。 Roth)考察湖南企业绿之韵公司. 罗斯此行携最新的研究成果,走进了以绿之韵集团为代表的中国本土企业,与中国的商业巨鳄、学者专家共同探讨共享经济时代下的市场设计话题。出席本 ...

诺贝尔经济学奖得主罗斯考察浏阳经开区企业

红网 - ‎Sep 20, 2016‎
红网综合讯据浏阳经开区消息9月20日上午,诺贝尔经济学奖获得者埃尔文•罗斯(Alvin E. Roth)一行来到浏阳经开区绿之韵集团考察。浏阳经开区党工委副书记、管委会主任郭力夫,绿之韵集团战略发展顾问、 ...

By the way, the food in Hunan is exotic, here's our lunch menu, which has some unusual items (translated for me by Ms Keny Chen):

Lunch Menu 午宴菜品
Cold Dishes|冷菜
Chrysanthemum with special sauce 凉拌苦菊
Vinegar walnut kernel 醋泡核桃仁
Preserved duck egg mixed with pepper 擂辣椒皮蛋
Sauced radish peels 萝卜皮
Salty chicken feet 盐焗凤爪
Fennel with special sauce 凉拌茴香
Soup|汤
海马人参乳鸽汤
Main Dishes|热菜
Lobster and salmon sashimi 龙虾三文鱼双拼刺身
Roast suckling pig 鸿运烤乳猪
Roasted goose 烧鹅
Braised local tortoise with soy sauce 红烧土乌龟
Stir-fry snake with spicy sauce 香辣蛇
Lactarius deliciosus braised in brown sauce 黄焖寒菌*
Steamed Leopard Coral Grouper 清蒸蓝东星斑
Steamed scallop with minced garlic and vermicelli 蒜蓉粉丝蒸扇贝
Sautéd razor shell 口味圣子王
Poached domestic chicken 清炖土鸡
Stir-fry snow pea and pleurotus nebrodensis (bailing mushroom) 荷兰豆炒白灵菇
Spiced beef 酱香肉
Steamed ribs with sticky rice and pumpkin 金瓜糯香骨
Stir-fry preserved taro stripe with dried paprika 干椒炒酸芋头丝
Stir-fry diced beef and capsicum 彩椒炒牛仔粒
Stir-fry shrimp with egg white 芙蓉百合
Stir-fry pickles with sliced conch 酸萝卜炒螺片
Stir-fry Chinese edible frog 爆炒田鸡
Stir-fry nostoc commune (agaric) 清炒地木耳
Stir-fry bitter melon with green pepper 清炒苦瓜
Stir-fry Chinese kale (Kai-lan) 清炒芥兰
Staples|主食
Fried Glutinous Rice Balls with Sesame 大麻果
Potsticker 锅饺

Saturday, September 24, 2016

Celebration of David Kreps

I was away and missed the academic festival to mark Dave Kreps' 65th birthday. But here's a nice account of it (after a non-sequitur first paragraph) by David Warsh at Economic Principals:
It Takes (an Invisible) College 

"A celebration last week of the sixty-fifth birthday of David Kreps, of Stanford University’s Graduate School of Business, marked the scholarly contributions of one of the leading figures in the integration of game theory into economics.  "

School choice in England


Friday, September 23, 2016

Resettlement as a matching problem: Bazzi, Gaduh, Rothenberg, and Wong on Population Resettlement in Indonesia

There's a lot of discussion of how best to resettle refugees internationally, and of course we might be able to learn a lot about that by looking at the resettlement of internally displaced people, and other migrants.  Here's a recent AER paper that looks at the matching component and finds that it matters who goes where.

Skill Transferability, Migration, and Development: Evidence from Population Resettlement in Indonesia
By Samuel Bazzi, Arya Gaduh, Alexander D. Rothenberg, and Maisy Wong

Abstract: We use a natural experiment in Indonesia to provide causal evidence
on the role of location-specific human capital and skill transferability in shaping the spatial distribution of productivity. From 1979–1988, the Transmigration Program relocated two million migrants from rural Java and Bali to new rural settlements in the Outer Islands. Villages assigned migrants from regions with more similar agroclimatic endowments exhibit higher rice productivity and nighttime light intensity one to two decades later. We find some evidence of migrants’ adaptation to agroclimatic change. Overall, our results suggest that
regional productivity differences may overstate the potential gains
from migration.  

Thursday, September 22, 2016

Reputation in online marketplaces

Two recent NBER papers tell us about trust, quality, and reputation in online marketplaces.

BUYING REPUTATION AS A SIGNAL OF QUALITY:
EVIDENCE FROM AN ONLINE MARKETPLACE
Lingfang (Ivy) Li, Steven Tadelis, Xiaolan Zhou
Working Paper 22584, http://www.nber.org/papers/w22584

ABSTRACT: Reputation is critical to foster trust in online marketplaces, yet leaving feedback is a public good that can be under-provided unless buyers are rewarded for it. Signaling theory implies that only high quality sellers would reward buyers for truthful feedback. We explore this scope for signaling using Taobao's "reward-for-feedback" mechanism and find that items with rewards
generate sales that are nearly 30% higher and are sold by higher quality sellers. The market design implication is that marketplaces can benefit from allowing sellers to use rewards to build reputations and signal their high quality in the process.
**********

Michael Luca
Working Paper 22616, http://www.nber.org/papers/w22616

ABSTRACT: Online marketplaces have proliferated over the past decade, creating new markets where none existed. By reducing transaction costs, online marketplaces facilitate transactions that otherwise would not have occurred and enable easier entry of small sellers. One central challenge faced by designers of online marketplaces is how to build enough trust to facilitate transactions between strangers. This paper provides an economist’s toolkit for designing online marketplaces, focusing on trust and reputation mechanisms.

Wednesday, September 21, 2016

Repugnance watch: Pokemon Go banned in Iran

Here's the BBC story, which also covers restrictions on the game elsewhere, for various reasons: Pokemon Go banned by Iranian authorities over 'security'

"The decision was taken by the High Council of Virtual Spaces, the official body overseeing online activity.
Iran follows a number of other countries in expressing its worries over security related to the game.
...
"Indonesia has banned police officers from playing the game while on duty, and a French player was arrested last month after straying on to a military base while trying to catch Pokemon.
A leading Saudi cleric said a fatwa (religious ruling) issued against an earlier Pokemon card game also applied to the new mixed-reality app.
The 16-year-old edict said the game contained "forbidden images" and violated an Islamic ban on gambling. But a fatwa's influence might not carry beyond that particular scholar's territory, and is not necessarily applicable to the whole country.
Earlier this week, authorities in New York state said they would ban some 3,000 registered sex offenders from playing Pokemon Go while they are on parole.
The ban is aimed at safeguarding the children who play the game."

Tuesday, September 20, 2016

Stable matching for university admissions in Vietnam?

Here's a proposal (in Vietnamese) to use a deferred acceptance algorithm to organize university admissions in Vietnam:

Kỳ thi THPT Quốc Gia 2016
Về việc áp dụng thuật toán DAA của Gale-Shapley trong xét tuyển – Đối Thoại Giáo Dục

Google translate renders the headline this way:
"National high school exams in 2016
On application of the algorithm of Gale-Shapley DAA in admissions - Dialogue Education"

Monday, September 19, 2016

Who Gets What and Why, in China

I'll be travelling to China today, to speak in Changsha and Lanzhou, as a guest of the Times Media Group, to talk about the Chinese edition of my book Who Gets What and Why.

Here's a news story...
诺奖得主来华:共享经济时代如何优化资源配置?
Nobel Laureate in China: how to optimize the sharing of economic resources?

Google translate has trouble with my name in Chinese:  here are some variants they produce:
Erwin · E · Ross (Alvin E. Roth)
Elvin Ross

Sunday, September 18, 2016

Public schools in Indianapolis advertise for enrollment, in competition with private schools

There's an enrollment contest underway in Indianapolis, and a new law against cash bonuses for referrals.
The Indianapolis Business Journal has the story:
Competition for school kids heats up across Indy

"Most Indianapolis kids went back to class in early August. But across town, billboards, yard signs and mailers put out by schools are making a last-minute pitch to parents: Enroll your child here.

"Public schools—including traditional, district-run schools and charters—are employing ever-more sophisticated advertising and marketing campaigns. The goal is to meet enrollment targets by the time the official state count day rolls around. This year, a school’s attendance on Sept. 16 determines its funding levels for the fall semester.
...
"Carpe Diem Meridian charter school’s 2015 marketing campaign tactic—offering $100 gift cards to anyone who referred a student who enrolled—was later that year made illegal by the Indiana General Assembly.

"The law says that a “school may not offer or give, as an enrollment incentive, any item that has monetary value, including cash or a gift card that may be used at a retail store, grocery store, online store, or other commercial enterprise” to prospective students in exchange for enrolling or to anyone who makes referrals."

Saturday, September 17, 2016

Unraveling of apprenticeships in Switzerland

The Neue Zurcher Zeitung has the story: Die heikle Jagd nach den besten Lehrlingen von Hansueli Schöchli
Die Lehrstellen in der Schweiz werden zum Teil «zu früh» vergeben. Absprachen zwischen den Lehrbetrieben wären ein Gegenmittel. Doch solche Absprachen scheitern oft.

Google translate: "The tricky hunt for the best apprentices--The apprenticeships in Switzerland are awarded partly "too early". Agreements between educational establishments would be an antidote. But such agreements often fail."

Friday, September 16, 2016

Decentralized College Admissions by Che and Koh

In the Journal of Political Economy:


We study decentralized college admissions with uncertain student preferences. Colleges strategically admit students likely to be overlooked by competitors. Highly ranked students may receive fewer admissions or have a higher chance of receiving no admissions than those ranked below. When students’ attributes are multidimensional, colleges avoid head-on competition by placing excessive weight on school-specific attributes such as essays. Restricting the number of applications or wait-listing alleviates enrollment uncertainty, but the outcomes are inefficient and unfair. A centralized matching via Gale and Shapley’s deferred acceptance algorithm attains efficiency and fairness but may make some colleges worse off than under decentralized matching.

The Handbook of Experimental Economics, volume 2, edited by John Kagel and Al Roth (forthcoming Sept 27:)


The Handbook of Experimental Economics, Volume 2 Hardcover –  forthcoming, September 27, 2016
by John H. Kagel (Editor), Alvin E. Roth (Editor)

from Princeton University Press
Table of Contents [PDF] pdf-icon


from Amazon

From the Back Cover

"This new volume of Kagel and Roth's indispensable handbook covers the latest dramatic developments that have led experimental economics into areas such as market design and neuroeconomics, and also offers fresh insights into more traditional areas. It is all here, and all told in a manner both informative and engaging."--Gary Bolton, University of Texas, Dallas
"Kagel and Roth have done it again. While the first volume of the Handbook showed how experimental economics had reached its maturity as a scientific method, this second volume shows just how wide its reach has become, and how deep these tools can take our understanding of economic theory and human behavior. This book will change the way the world views economics."--James Andreoni, University of California, San Diego
"The contributors provide insights that will be invaluable to anyone seeking a deeper understanding of the issues at hand. I know of no other book that covers the same breadth of material in the same way. People will use this as a reference book for many years to come."--Tim Salmon, Southern Methodist University
"A worthy successor to the first volume. This ambitious and well-written book will appeal to a broad economic audience."--Tom Wilkening, University of Melbourne
"I wish every economist and economics graduate student would read this book. Those who are considering running experiments should be forced to; this is a bible in how to run good experiments. Every chapter is amazingly comprehensive and has been written by a true expert in the field. But economists who would never dream about running an experiment can benefit from reading this just as much. The beauty of experiments is that they force theorists to think carefully about their theories."--Richard Thaler, Cornell University
"This Handbook surveys one of the most important developments in economics in the last decade, the flowering of experimental economics. Led by two of the leaders of current economic theory and experimental economics, an impressive group of researchers provides the reader with an excellent up-to-date overview of one of the most fascinating and promising areas of current economic research."--Ariel Rubinstein, Princeton University
"The Handbook is not only a contribution to experimental economics, it is a major contribution to social science. It successfully combines the rigor and clarity of economic analysis with a commitment to open-minded examination of data, and a refreshing willingness to question dogma. Every student of human choice and action will find this text useful."--Daniel Kahneman, The Woodrow Wilson School of Public and International Affairs, Princeton University
"Experimental economics comes of age with this volume. At last the dust begins to clear, and it becomes possible to confront theory with coherent and reliable laboratory data."--Ken Binmore, University College of London

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

Wednesday, September 14, 2016

Quién obtiene qué y por qué. Who gets what and why, in Spanish

Who gets what and why is coming out in Spanish (in October). The publisher is Antoni Bosch, the economist.



Quién obtiene qué y por qué

LA NUEVA ECONOMÍA DEL DISEÑO DE MERCADOS

Alvin E. Roth
2016 (octubre)