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Transaction Fee Mechanism Design studies auctions run by untrusted miners for transaction inclusion in a blockchain. Under previously-considered desiderata, an auction is considered `good' if, informally-speaking, each party (i.e., the miner, the users, and coalitions of both miners and users) has no incentive to deviate from the fixed and pre-determined protocol. In this paper, we propose a novel desideratum for transaction fee mechanisms. We say that a TFM is off-chain influence proof when the miner cannot achieve additional revenue by running a separate auction off-chain. While the previously-highlighted EIP-1559 is the gold-standard according to prior desiderata, we show that it does not satisfy off-chain influence proofness. Intuitively, this holds because a Bayesian revenue-maximizing miner can strictly increase profits by persuasively threatening to censor any bids that do not transfer a tip directly to the miner off-chain. On the other hand, we reconsider the Cryptographic (multi-party computation assisted) Second Price Auction mechanism, which is technically not `simple for miners' according to previous desiderata (since miners may wish to set a reserve by fabricating bids). We show that, in a slightly different model where the miner is allowed to set the reserve directly, this auction satisfies simplicity for users and miners, and off-chain influence proofness. Finally, we prove a strong impossibility result: no mechanism satisfies all previously-considered properties along with off-chain influence proofness, even with unlimited supply, and even after soliciting input from the miner.

We conduct an incentivized lab experiment to test participants' ability to understand the DA matching mechanism and the strategyproofness property, conveyed in different ways. We find that while many participants can (using a novel GUI) learn DA's mechanics and calculate its outcomes, such understanding does not imply understanding of strategyproofness (as measured by specially designed tests). However, a novel menu description of strategyproofness conveys this property significantly better than other treatments. While behavioral effects are small on average, participants with levels of strategyproofness understanding above a certain threshold play the classical dominant strategy at very high rates.

We study the communication complexity of truthful combinatorial auctions, and in particular the case where valuations are either subadditive or single-minded, which we denote with $\mathsf{SubAdd}\cup\mathsf{SingleM}$. We show that for three bidders with valuations in $\mathsf{SubAdd}\cup\mathsf{SingleM}$, any deterministic truthful mechanism that achieves at least a $0.366$-approximation requires $\exp(m)$ communication. In contrast, a natural extension of [Fei09] yields a non-truthful $\mathrm{poly}(m)$-communication protocol that achieves a $\frac{1}{2}$-approximation, demonstrating a gap between the power of truthful mechanisms and non-truthful protocols for this problem. Our approach follows the taxation complexity framework laid out in [Dob16b], but applies this framework in a setting not encompassed by the techniques used in past work. In particular, the only successful prior application of this framework uses a reduction to simultaneous protocols which only applies for two bidders [AKSW20], whereas our three-player lower bounds are stronger than what can possibly arise from a two-player construction (since a trivial truthful auction guarantees a $\frac{1}{2}$-approximation for two players).

Stable matchings are a cornerstone of market design, with numerous practical deployments backed by a rich, theoretically-tractable structure. However, in school-choice problems, stable matchings are not Pareto optimal for the students. Priority-neutral matchings, introduced by Reny (AER, 2022), generalizes the set of stable matchings by allowing for certain priority violations, and there is always a Pareto optimal priority-neutral matching. Moreover, like stable matchings, the set of priority-neutral matchings forms a lattice. We study the structure of the priority-neutral lattice. Unfortunately, we show that much of the simplicity of the stable matching lattice does not hold for the priority-neutral lattice. In particular, we show that the priority-neutral lattice need not be distributive. Moreover, we show that the greatest lower bound of two matchings in the priority-neutral lattice need not be their student-by-student minimum, answering an open question. This show that many widely-used properties of stable matchings fail for priority-neutral matchings; in particular, the set of priority-neutral matchings cannot be represented by via a partial ordering on a set of rotations. However, by proving a novel structural property of the set of priority-neutral matchings, we also show that not every lattice arises as a priority-neutral lattice, which suggests that the exact nature of the family of priority-neutral lattices may be subtle.

We study various novel complexity measures for two-sided matching mechanisms, applied to the two canonical strategyproof matching mechanisms, Deferred Acceptance (DA) and Top Trading Cycles (TTC). Our metrics are designed to capture the complexity of various structural (rather than computational) concerns, in particular ones of recent interest within economics. We consider a unified, flexible approach to formalizing our questions: Define a protocol or data structure performing some task, and bound the number of bits that it requires. Our main results apply this approach to four questions of general interest; for mechanisms matching applicants to institutions, our questions are: (1) How can one applicant affect the outcome matching? (2) How can one applicant affect another applicant's set of options? (3) How can the outcome matching be represented / communicated? (4) How can the outcome matching be verified? Holistically, our results show that TTC is more complex than DA, formalizing previous intuitions that DA has a simpler structure than TTC. For question (2), our result gives a new combinatorial characterization of which institutions are removed from each applicant's set of options when a new applicant is added in DA; this characterization may be of independent interest. For question (3), our result gives new tight lower bounds proving that the relationship between the matching and the priorities is more complex in TTC than in DA. We nonetheless showcase that this higher complexity of TTC is nuanced: By constructing new tight lower-bound instances and new verification protocols, we prove that DA and TTC are comparable in complexity under questions (1) and (4). This more precisely delineates the ways in which TTC is more complex than DA, and emphasizes that diverse considerations must factor into gauging the complexity of matching mechanisms.

A menu description presents a mechanism to player $i$ in two steps. Step (1) uses the reports of other players to describe $i$'s menu: the set of $i$'s potential outcomes. Step (2) uses $i$'s report to select $i$'s favorite outcome from her menu. Can menu descriptions better expose strategyproofness, without sacrificing simplicity? We propose a new, simple menu description of Deferred Acceptance. We prove that -- in contrast with other common matching mechanisms -- this menu description must differ substantially from the corresponding traditional description. We demonstrate, with a lab experiment on two elementary mechanisms, the promise and challenges of menu descriptions.

We consider the problem of implementing a fixed social choice function between multiple players (which takes as input a type $t_i$ from each player $i$ and outputs an outcome $f(t_1,\ldots, t_n)$), in which each player must be incentivized to follow the protocol. In particular, we study the communication requirements of a protocol which: (a) implements $f$, (b) implements $f$ and computes payments that make it ex-post incentive compatible (EPIC) to follow the protocol, and (c) implements $f$ and computes payments in a way that makes it dominant-strategy incentive compatible (DSIC) to follow the protocol. We show exponential separations between all three of these quantities, already for just two players. That is, we first construct an $f$ such that $f$ can be implemented in communication $c$, but any EPIC implementation of $f$ (with any choice of payments) requires communication $\exp(c)$. This answers an open question of [FS09, BBS13]. Second, we construct an $f$ such that an EPIC protocol implements $f$ with communication $C$, but all DSIC implementations of $f$ require communication $\exp(C)$.

We study the strategic simplicity of stable matching mechanisms where one side has fixed preferences, termed priorities. Specifically, we ask which priorities are such that the strategyproofness of deferred acceptance (DA) can be recognized by agents unable to perform contingency reasoning, that is, \emph{when is DA obviously strategyproof} (Li, 2017)? We answer this question by completely characterizing those priorities which make DA obviously strategyproof (OSP). This solves an open problem of Ashlagi and Gonczarowski, 2018. We find that when DA is OSP, priorities are either acyclic (Ergin, 2002), a restrictive condition which allows priorities to only differ on only two agents at a time, or contain an extremely limited cyclic pattern where all priority lists are identical except for exactly two. We conclude that, for stable matching mechanisms, the tension between understandability (in the sense of OSP) and expressiveness of priorities is very high.

We study the stable marriage problem in two-sided markets with randomly generated preferences. We consider agents on each side divided into a constant number of "soft tiers", which intuitively indicate the quality of the agent. Specifically, every agent within a tier has the same public score, and agents on each side have preferences independently generated proportionally to the public scores of the other side. We compute the expected average rank which agents in each tier have for their partners in the men-optimal stable matching, and prove concentration results for the average rank in asymptotically large markets. Furthermore, we show that despite having a significant effect on ranks, public scores do not strongly influence the probability of an agent matching to a given tier of the other side. This generalizes results of [Pittel 1989] which correspond to uniform preferences. The results quantitatively demonstrate the effect of competition due to the heterogeneous attractiveness of agents in the market, and we give the first explicit calculations of rank beyond uniform markets.

The seminal book of Gusfield and Irving [GI89] provides a compact and algorithmically useful way to represent the collection of stable matches corresponding to a given set of preferences. In this paper, we reinterpret the main results of [GI89], giving a new proof of the characterization which is able to bypass a lot of the "theory building" of the original works. We also provide a streamlined and efficient way to compute this representation. Our proofs and algorithms emphasize the connection to well-known properties of the deferred acceptance algorithm.

A breakthrough of Ashlagi, Kanoria, and Leshno [AKL17] found that imbalance in the number of agents on either side of a random matching market has a profound effect on the market's expected characteristics. Specifically, across all stable matchings, the "long side" (i.e. the side with a greater number of agents) receives significantly worse matches in expectation than the short side. Intuitively, this occurs because an agent on the long side is essentially unneeded to create a stable matching -- a matching could form almost as easily without them. Thus, an agent on the long side has very little market power, and must settle for a match which is not much better than a random assignment. We provide a new and simpler proof for a result of [AKL17] which formalizes this intuition.

State-of-the-art posted-price mechanisms for submodular bidders with $m$ items achieve approximation guarantees of $O((\log \log m)^3)$ [Assadi and Singla, 2019]. Their truthfulness, however, requires bidders to compute an NP-hard demand-query. Some computational complexity of this form is unavoidable, as it is NP-hard for truthful mechanisms to guarantee even an $m^{1/2-\varepsilon}$-approximation for any $\varepsilon > 0$ [Dobzinski and Vondr\'ak, 2016]. Together, these establish a stark distinction between computationally-efficient and communication-efficient truthful mechanisms. We show that this distinction disappears with a mild relaxation of truthfulness, which we term implementation in advised strategies, and that has been previously studied in relation to "Implementation in Undominated Strategies" [Babaioff et al, 2009]. Specifically, advice maps a tentative strategy either to that same strategy itself, or one that dominates it. We say that a player follows advice as long as they never play actions which are dominated by advice. A poly-time mechanism guarantees an $\alpha$-approximation in implementation in advised strategies if there exists poly-time advice for each player such that an $\alpha$-approximation is achieved whenever all players follow advice. Using an appropriate bicriterion notion of approximate demand queries (which can be computed in poly-time), we establish that (a slight modification of) the [Assadi and Singla, 2019] mechanism achieves the same $O((\log \log m)^3)$-approximation in implementation in advised strategies.

The Congressional Research Service report "Iran: Background and U.S. Policy" delves into Iran's recent military setbacks and uncertainties surrounding its ballistic missile program. It outlines the historical tensions between Iran and the United States, focusing on Iran's nuclear program, human rights violations, and support for armed groups. The report also examines the impact of recent events on Iran's regional influence and potential future actions by the Iranian government, such as diplomatic reengagement or nuclear weapon pursuit. Additionally, it provides an in-depth overview of Iran's background, U.S. policy towards Iran, foreign relations, military capabilities, nuclear program, and recent events involving Iran and the U.S. [Extracted from the article]

The document details the Congressional reporting requirements concerning Iran, covering topics such as missile activities, nuclear program, human rights, and relations with other countries. It highlights that numerous congressional committees have received reports on Iran over the past decade, with some reports accessible to the public. Congress utilizes these reports to evaluate their impact on policymaking and decides whether to modify the information demanded from the executive branch. The document includes comprehensive tables outlining legislative reporting requirements from the 111th to the 118th Congress, encompassing a broad array of Iran-related issues and themes. [Extracted from the article]

The article focuses on the challenges facing U.S. policymakers in light of the Taliban's return to power in Afghanistan. Topics include counterterrorism efforts regarding the Islamic State (ISIS) and Al Qaeda, the severe restrictions imposed on women and girls, and the ongoing humanitarian and economic crises in the country.

The article discusses the ongoing conflict between Israel and Lebanese Hezbollah, which escalated following Hamas's attacks on Israel in October 2023. It details the military exchanges, casualties, evacuations, and the humanitarian crisis in Lebanon. It also highlights Israel's military responses, including strikes on Hezbollah's leadership, and the potential implications for Iran, the U.S., and Lebanese politics.

The article focuses on Hezbollah's role as a significant Iranian-backed militia and its impact on regional stability and U.S. interests. Topics include the group's leadership and military capabilities, its involvement in Lebanese politics and social services, and its ongoing conflict with Israel and the implications for U.S. policy.

The article offers information related to Israel and Hamas October 2023 Conflict. It mentions Israel's cabinet formally declared war on Hamas and has initiated efforts to recover hostages, begun an aerial bombardment campaign against militants in Gaza. It also mentions Israel Defense Forces has called all civilians to evacuate southward and U.S. Secretary of State Antony Blinken and Israel have agreed to develop a plan that will enable international humanitarian aid to reach civilians in Gaza.

The article provides an overview of Iran's background and U.S. policy, highlighting Iran's regional influence and U.S. concerns about its nuclear program and support for armed groups. Topics discussed include historical U.S.-Iran relations, Trump and Biden administration policies, and developments in 2023, including attacks on Gulf shipping, diplomatic efforts, and a prisoner exchange.

The article presents a report from the U.S. Congressional Research Service on U.S. sale of F-16 fighter aircraft to Turkey. The sale could extend the service life of Turkey's aircraft fleet and ensure its continued interoperability within NATO, but it faces congressional review and considerations related to NATO unity, Turkish-Swedish relations, and other geopolitical factors.

A survey indicates that student complaints led legislators in 20 states to mandate that higher education institutions develop policies on oral English proficiency of instructors, including language certification for international teaching assistants. Many institutions responded with policies requiring formal language testing and remedial instruction when needed. (MSE)

The article provides an overview of major issues and the state of U.S. relations with Turkey. It discusses the complex geopolitical environment in which U.S.-Turkey relations occur, including Turkey's ongoing recovery from the 2023 earthquakes. Key points of tension between the two countries are highlighted, such as U.S. support for Syrian Kurds and Turkey's procurement of Russian S-400 defense systems.

The article focuses on Afghanistan's background and U.S. policy following the withdrawal of U.S. and international forces and the subsequent Taliban takeover. Topics discussed include the impact of the Taliban's rule on counterterrorism efforts, women's rights, and efforts to relocate U.S. citizens and Afghan partners.

The article discusses implications of Russia's invasion of Ukraine and the ensuing war on the countries of the Middle East and North Africa (MENA), a region of continuing strategic and foreign policy salience to Congress. Topics include humanitarian effects of war in the MENA region, because of increased volatility in energy and food commodity markets, decisions related to diplomacy, and the provision of military support, and enforcement of sanctions.

The article focuses on Congress has played a key role in shaping U.S. policy toward Iran, providing for extensive U.S. sanctions, providing aid and authorizing arms sales to partners threatened by Iran, seeking to influence negotiations over Iran's nuclear program. It mentions government's support for armed proxies and terrorist groups, its human rights violations, and its increasingly close relationships with Russia and China have all posed challenges for the U.S.

The article focuses on the U.S. Congressional Research Service it reports on the complicated geopolitical environment of U.S. relations with Turkey, it highlights tensions that have arisen due to disagreements over issues such as Syrian Kurds and Turkey's procurement of a Russian defense system. It discusses the potential implications of U.S. congressional action regarding Turkey and rivals, as well as Turkey's foreign policy approach and ongoing conflict in Syria.

The article offers information that in the year 2021, Afghanistan, U.S. and international forces departed after nearly two decades of operations, leading to the collapse of the Afghan government and military forces, and the Taliban's return to power. The Taliban government is dominated by former officials from their prior rule or longtime loyalists, prioritizing internal cohesion over outreach to other segments of Afghan society.

The article focuses on U.S. sanctions on Iran, detailing their evolution and impact since the Iranian Revolution of 1979. It outlines how these sanctions aim to deter Iran's support for terrorism, nuclear development, and human rights abuses while affecting Iran's economy. It discusses the legal framework of sanctions, the role of Congress in shaping policy, and the U.S. President, Joe Biden Administration's approach amid ongoing tensions.

The article focuses on Iran's support for armed groups in the Middle East as a means to further its regional objectives and the implications for U.S. policy. Topics include the historical context of Iran's foreign policy and its backing of groups like Hezbollah and Hamas, the recent escalation of attacks attributed to these groups, and the U.S. government's strategies to deter and respond to these threats while avoiding direct confrontation with Iran.

The article discusses the U.S. Congressional Research Service and focuses on the U.S. sanctions on Iran since 1979, it reports that on its behavior, support for terrorism, nuclear programs, regional interventions, and human rights abuses. It explains the sanctions, historical background, of U.S, Iran relations, the Joint Comprehensive Plan of Action (JCPOA), Biden Administration, current sanctions landscape, and Iran's efforts to mitigate their impact.

The article provides an analysis of the implications of Russian invasion of Ukraine and the ensuing war in 2022 on Middle East and North Africa (MENA) region. Topics include the risk of instability in the region and complexities to some regional relationships posed by the Russia-Ukraine war, an overview and possible issues for the U.S. Congress such as U.S. sanctions relating to Russia and how the sanctions may be implemented in the MENA region, and the effects of the war on energy prices.

The article provides an overview of the U.S. relations with Turkey. It mentions Russia's invasion of Ukraine has heightened challenges Turkey faces in balancing relations with the two countries, with implications for U.S.-Turkey ties. It also mentions in late 2021, an ongoing currency crisis accelerated after he installed a central bank governor who lowered interest rates, generating major domestic concern about inflation and the country's future financial stability.

The article provides an overview of the evolving U.S. national security strategy in the MENA region (Middle East, North Africa). It highlights various challenges faced by the U.S., including multilateral impasses with Iran over its nuclear program, leadership transitions in Israel and Palestine, and geopolitical issues such as freedom of navigation in waterways. It outlines potential policies that the 118th Congress may consider, including proposals to fund and authorize U.S. programs.

The article presents a timeline of the Turkey-U.S. relationship from 1945 to the present. The timeline covers the strategic cooperation between the countries in the early Cold War; the challenges and difficulties during the Cyprus conflict and the Kurdish insurgency; and the renewed military cooperation during the Gulf War.

The article focuses on the deteriorating status of women and girls in Afghanistan under Taliban rule as well as U.S. policy options in response. Topics include the background on the status of women in Afghanistan, the Taliban's treatment of women under renewed rule, and recent restrictions on women's rights, education, and employment.

The article provides information on the U.S. military withdrawal and Taliban takeover in Afghanistan in 2021. The Taliban movement was formed by Afghan Muslim clerics and students in 1993. The deployment of military forces to Afghanistan was prompted by the refusal of the Taliban to hand over Al Qaeda terrorists. The Department of Defense spent 837.3 billion dollars on the war in Afghanistan from September 11, 2001 through March 31, 2021.

The article presents a report by the U.S. Congressional Research Service which describes background and U.S. foreign policy concerns in Afghanistan. Topics include the impact of U.S. military disengagement on Afghan forces and security dynamics; the impact of U.S. military disengagement on democracy and human rights in Afghanistan; and issues for Congress regarding the same.

The article focuses on Congress shaped U.S. national security policy toward several critical crises and during the decade from 2011 through 2020 towards Middle East. It mentions U.S. Constitution, legislative and executive branches of government use a range of tools in exercising their respective foreign policy powers. It also mentions Congress also provided for extensive U.S. sanctions targeting Iran for its nuclear program, weapons proliferation, restrictions on human rights and democracy.

The article addresses frequently asked questions regarding the U.S. military drawdown in Afghanistan. It discusses the missions of U.S. forces in Afghanistan and concerns on the impact of the drawdown on U.S. policy interests. Questions addressed include the reason behind the decline in U.S. force levels in the country under former U.S. President Donald Trump's administration and the reaction of Afghans and the Taliban to the drawdown.

The article presents a report of the U.S. Congressional Research Service (CRS), that talks about Turkey's July 2019 acquisition of an S-400 surface-to-air defense system from Russia sparked debate about possible U.S. sanctions against Turkey, a North Atlantic Treaty Organization (NATO) ally under the Countering U.S.'s Adversaries through Sanctions Act.

The article focuses on U.S.-Iran tensions have heightened significantly, and evolved into conflict after U.S. military forces killed Qasem Soleimani, the commander of the Iran's Islamic Revolutionary Guard Corps-Quds Force. It mentions U.S.-Iran tensions are the 2018 Trump Administration withdrawal from the 2015 multilateral nuclear agreement with Iran Joint Comprehensive Plan of Action (JCPOA). It also mentions Iran has continued all its operations for wrestling with the COVID-19 pandemic.

The article reports that Afghanistan was elevated as a significant U.S. foreign policy concern in 2001 in response to the terrorist attacks of September 11, 2001 led a military campaign against Al Qaeda and the Taliban government that harbored and supported it. It mentions COVID-19, which further complicates many of the dynamics and risk due to a public health system. It also mentions Taliban have maintained their refusal to engage with the Afghan government's negotiating team.

The article presents the U.S. Congressional Research Service report on the history of U.S.-Turkey tensions. Topics discussed include Turkey's strategic orientation and U.S.- North Atlantic Treaty Organization defense cooperation; Turkey's purchase of a Russian S- 400 surface-to-air defense system, and U.S. response; and U.S.-Turkey tensions in Syria related to Kurdish-led militias.

The article offers information on the transcripts of interviews with more than 400 U.S. and other policymakers that were carried out between 2014 and 2018 by the Special Inspector General for Afghanistan Reconstruction. It mentions the U.S. policies in Afghanistan often were poorly planned, resourced; and also mentions that anti-corruption, counternarcotics, and other mission priorities rarely fit neatly under one agency or department's purview.

The article focuses on the killing of Islamic Revolutionary Guard Corps-Quds Force (IRGC-QF) Commander, who regarded as one of the most powerful and important officials in Iran, has potentially dramatic implications for the U.S. It mentions the relations between Iran and the U.S. have been mostly confrontational since 1979; and also mentions that Iran supports a number of armed groups in Iraq, including U.S. designated terrorist organizations such as Kata'ib Hezbollah (KH).

The article informs on political and economic challenges faced by Turkey. Topics include Turkey's October 2019 incursion into northeastern Syria; Turkey's rationale and its implications for North Atlantic Treaty Organization; and U.S. sanctions and other U.S. actions against Turkey. It also informs on political developments under Turkish President Recep Tayyip Erdogan's rule.

The article presents a report by the U.S. Congressional Research Service which describes background, current status, and U.S. policy initiatives for Al Qaeda. It mentions that the U.S. policymakers seek to combat Al Qaeda and other terrorist groups by addressing the drivers of terrorism through counter- and de-radicalization programs, by countering the financing of Al Qaeda.

The article explores the constitutional referendum in Turkey to be held in April 2017. Topics include the proposed amendments to the 1982 constitution that would change Turkey's system of governance, changes to the government structure and electoral system, rule of law, media freedom, and economic issues. Also discussed are concerns whether the elections wil be fair and European countries' efforts to prevent Turkish officials from promoting the referendum.