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Checkout charity is the solicitation of charitable donations from consumers during the checkout process via a cashier or computer automated system. Although checkout charity has become ubiquitous in the retail industry, consumers often felt pressured to donate and wished not to be asked to donate. How can we encourage consumers to donate when they encounter online checkout charity and make feel good about it? This study tried to address this question by identifying how online shoppers’ attitudes and donation behavior could be influenced by donation payment method based on mental accounting. The result confirms that requesting a donation in reward points would enhance consumers’ attitude toward the retailer and their intention to donate to an online checkout charity. This study provides important managerial implications for companies, charities, and practitioners regarding how they can improve their online checkout charity practice to increase donations and sales and garner the benefits of enhanced corporate image by aligning themselves with charities.

This paper studies the effect of the economic impact payment (EIP) on individual contributions to COVID-19 mitigation efforts in the USA, where the mitigation efforts are measured by the reduction of daily human mobility. I empirically estimate the effect of the EIP in April 2020 and use cellphone GPS data of 45 million smartphone devices as a proxy for human mobility across 216,069 Census Block Groups. The results show that when receiving the EIP, households significantly increased “Median Home Dwell Time” by an average of 3–5% (about 26–45 min). The paper highlights this unintended effect of the EIP, namely, that in addition to providing economic assistance, the EIP also helped increase individual contributions to mitigation efforts that slowed COVID-19 virus transmission in early 2020. Supplementary Information The online version supplementary material available at 10.1007/s00181-021-02117-0.

This paper examines the behaviour of mental health care providers in response to marginal payment incentives induced by a discontinuous per diem reimbursement schedule with varying tariff rates over the length of stay. The analyses use administrative data on 12,627 cases treated in 82 psychiatric hospitals and wards in Germany. We investigate whether substantial reductions in marginal reimbursement per inpatient day led to strategic discharge behaviour once a certain length of stay threshold is exceeded. The data do not show gaps and bunches at the duration of treatment when marginal reimbursement decreases. Using logistic regression models, we find that providers did not react to discontinuities in marginal reimbursement by significantly reducing inpatient length of stay around the threshold. These findings are robust in terms of different model specifications and subsamples. The results indicate that if regulators aim to set incentives to decrease LOS, this might not be achieved by cuts in reimbursement over LOS. Electronic supplementary material The online version of this article (10.1007/s10198-020-01241-5) contains supplementary material, which is available to authorized users.

Unwarranted variation in the quality of care challenges the sustainability of healthcare systems. Especially in decentralised healthcare systems, it is crucial to understand the drivers behind regional differences in hospital qualities such as unplanned readmissions. This paper examines the factors that influence the risk of unplanned hospital readmission and the geographic disparity of readmission rate in Italy. We use hospital discharge data from 2010 to 2015 for patients above 65 years old admitted with Acute Myocardial Infarction. Employing hierarchical models, we identified the patient and hospital-level determinants for unplanned readmission. In line with the literature, the risk of readmission increases with age and being male, while hospitals with higher patient volume and capacity tend to have lower unplanned readmission. In particular, we find that after patient risk-adjustments, there are differential effects of hospitalisation length-of-stay on the probability of readmission across the hospitals that are governed by different payment systems. For hospitals under a prospective payment system, the effect of length-of-stay in reducing the probability of readmission is weaker than hospitals under an ex-post global budget, but the overall readmission rates are the lowest. Moreover, there are substantial geographic variations in readmission rate across Local Health Authority and regions, and these variations of unplanned readmission are explained by differences in hospital length-of-stay and surgical procedures used. Our results demonstrate that differential hospital behaviours can be one of the potential mechanisms that drive geographic quality disparities.

ZusammenfassungNoch zur Jahreswende 2019/2020 prognostizierten die an der Gemeinschaftsdiagnose beteiligten Wirtschaftsforschungsinstitute für 2020 staatliche Budgetüberschüsse von 21 Mrd. bis 31 Mrd. Euro. Sie gingen von einer Fortsetzung des Aufschwungs aus und erwarteten eine weitere Besserung der staatlichen Finanzlage. Die Staatsfinanzen waren fast ein Jahrzehnt von steigenden Budgetüberschüssen geprägt. Die Corona-Krise verschlechtert die Finanzlage schlagartig; sie wird 2020 zu einem historisch hohen Defizit und einem rasanten Anstieg der Staatsschuldenquote führen. Dank der komfortablen Finanzlage zu Beginn der Corona-Krise und der flexibel ausgestalteten Schuldenbremse verfügt der Staat aber über ausreichende fiskalische Spielräume, um Rettungsschirme und Konjunkturpakete von historischem Ausmaß zu finanzieren.

The purchaser of pontoons held liable for late payment of the final installment of the purchase price because the pontoons had passed the relevant safety inspection, although the government audit bureau did not verify the funds to pay the final installment until two years later.

The Defendant defended that according to Article 22 of the Insurance Law, when lodging a claim with the insurer for payment of indemnities or insurance benefits in accordance with the insurance contract after the occurrence of an event, the insured should provide to the insurer all proofs and information he could provide pertinent to determining the nature or cause of, the extent of the losses due to, and other circumstances of the insured event.

Payment channel networks provide a fast and scalable solution to relay funds, acting as a second layer to slower and less scalable blockchain protocols. In this paper, we present an accessible, low-cost attack in which the attacker paralyzes multiple payment network channels for several days. The attack is based on overloading channels with requests that are kept unresolved until their expiration time. Reaching the maximum allowed unresolved requests (\(\mathtt {HTLCs}\)) locks the channel for new payments. The attack is in fact inherent to the way off-chain networks are constructed, since limits on the number of unresolved payments are derived from limits on the blockchain. We consider three versions of the attack: one in which the attacker attempts to block as many high liquidity channels as possible, one in which it disconnects as many pairs of nodes as it can, and one in which it tries to isolate individual nodes from the network. We evaluate the costs of these attacks on Bitcoin’s Lightning Network and compare how changes in the network have affected the cost of attack. Specifically, we consider how recent changes to default parameters in each of the main Lightning implementations contribute to the attacks. Finally, we suggest mitigation techniques that make these attacks much harder to carry out.

Light clients, also known as Simple Payment Verification (SPV) clients, are nodes which only download a small portion of the data in a blockchain, and use indirect means to verify that a given chain is valid. Instead of validating blocks, they assume that the chain favoured by the blockchain’s consensus algorithm only contains valid blocks, and that the majority of block producers are honest. By allowing such clients to receive fraud proofs generated by fully validating nodes that show that a block violates the protocol rules, and combining this with probabilistic sampling techniques to verify that all of the data in a block actually is available to be downloaded so that fraud can be detected, we can eliminate the honest-majority assumption for block validity, and instead make much weaker assumptions about a minimum number of honest nodes that rebroadcast data. Fraud and data availability proofs are key to enabling on-chain scaling of blockchains while maintaining a strong assurance that on-chain data is available and valid. We present, implement, and evaluate a fraud and data availability proof system.

The Plaintiff-Time Charterer sued the Defendant-Port Operator in tort arising out damage to a vessel caused by the grab of the Defendant’s crane during discharge operations. The Plaintiff claimed that the Defendant was fully responsible for the vessel’s damage and should bear the full amount of liability for the losses the Plaintiff incurred from maintenance, repair, and other related expenses, plus loss of profits and ship detention expenses. The Defendant denied that it was at fault and also asserted that the Plaintiff did not standing to sue since it was not the ship owner or demise charterer. In awarding USD250,358.40 and EUR39,096.27 to the Plaintiff, the court determined that the Plaintiff had the capacity to file suit against that the Defendant since the damage occurred while the vessel was under the Plaintiff’s control, and the Time Charter Party gave the Plaintiff a legal interest in the vessel by making it responsible for any damage and repairs sustained during discharge operations. The court also granted recovery for the maintenance/repair costs, surveyor inspection fees, and fuel losses because each of those costs was reasonable and necessary for the Plaintiff to incur as a result of the accident. However, some costs, including sewage treatment expenses and the travel expenses for the ship owner’s representative were not reasonable and necessary, and the Plaintiff could not recover for loss of hire or profits since it had failed to prove what its income was prior to the accident and that the nature of the damages caused hire payments to cease.

The security of blockchain based decentralized ledgers relies on consensus protocols executed between mutually distrustful parties. Such protocols incur delays which severely limit the throughput of such ledgers. Payment and state channels enable execution of offchain protocols that allow interaction between parties without involving the consensus protocol. Protocols such as Hashed Timelock Contracts (HTLC) and Sprites (FC’19) connect channels into Payment Channel Networks (PCN) allowing payments across a path of payment channels. Such a payment requires each party to lock away funds for an amount of time. The product of funds and locktime is the collateral of the party, i.e., their cost of opportunity to forward a payment. In the case of HTLC, the locktime is linear to the length of the path, making the total collateral invested across the path quadratic in size of its length. Sprites improved on this by reducing the locktime to a constant by utilizing smart contracts. Atomic Multi-Channel Updates (AMCU), published at CCS’19, introduced constant collateral payments without smart contracts. In this work we present the Channel Closure attack on AMCU that allows a malicious adversary to make honest parties lose funds. Furthermore, we propose the Payment Trees protocol that allows payments across a PCN with linear total collateral without the aid of smart contracts; a competitive performance similar to Sprites, and yet compatible to Bitcoin.

(a) Situation faced: One large set of problems in Australian agricultural supply chains comprises liquidity and payment certainty: Farmers are typically paid for their goods after long delays, and sometimes payment fails altogether. At the same time, first buyers of crops (exporters, traders, processors, feedlots) have limited funds as they, like the farmers, have little access to financing, such as obtaining a loan against a quantity of the harvested crops. Financiers are often unwilling or unable to offer financing against such assets because of insufficient visibility—that is, the ability to see and verify the assets’ information, or the high cost of obtaining it. These liquidity and financing shortages are harmful to the Australian agricultural industry. (b) Action taken: The AgriDigital founding team knew these issues first hand, and, seeing early on the opportunities created by blockchain technology for their industry, founded the company to address these key challenges using emerging technologies. Their core idea was that digital trust could be generated across agri-supply chains using blockchain technology to create secure digital assets representing harvested crops, which would then become the foundation data layer to facilitate trade and finance solutions. Effectively conducting process innovation across the whole industry, AgriDigital first ran three pilots to gain an understanding of the needs and requirements of the various stakeholders. (c) Results achieved: Based on these pilots, two outcomes were implemented: (1) the blockchain part of the technology was spun out into a foundation, Geora, and generalized for other industries, and (2) AgriDigital developed a final product using Geora’s blockchain technology to expose a registry of assets using which financiers could deliver financing in a secure and streamlined way. In the second half of 2019, 75 growers and 6 buyers were already using the combined solution, from which 122,000 bales of cotton and 34,000 tons of grain, with a total value of US$18.5 million, were financed. (d) Lessons learned: The key lesson learned from running the pilots was that the emerging blockchain technology can help to improve trust, asset management, and payments in agri-supply chains but that using blockchain technology requires specific, detailed expertise. Therefore, a digital toolkit that makes the benefits of blockchain to a wide range of users is of real value. Confidentiality and flexibility requirements among the stakeholders must also be ensured. Next to these technological lessons learned are that good behavior should be incented; supply chain stakeholders have low technical capabilities, and on-chain payments are still a challenge.

The Plaintiff alleged that the Defendant entrusted it to perform freight forwarding services for the shipment of storage batteries from the port of Shanghai to Matadi, Democratic Republic of the Congo. The Plaintiff paid freight to the ocean carrier in advance, but the Defendant did not reimburse the Plaintiff, despite several requests for payment.

In this paper we extend the attack landscape of bribing attacks on cryptocurrencies by presenting a new method, which we call Pay-To-Win (P2W). To the best of our knowledge, it is the first approach capable of facilitating double-spend collusion across different blockchains. Moreover, our technique can also be used to specifically incentivize transaction exclusion or (re)ordering. For our construction we rely on smart contracts to render the payment and receipt of bribes trustless for the briber as well as the bribee. Attacks using our approach are operated and financed out-of-band i.e., on a funding cryptocurrency, while the consequences are induced in a different target cryptocurrency. Hereby, the main requirement is that smart contracts on the funding cryptocurrency are able to verify consensus rules of the target. For a concrete instantiation of our P2W method, we choose Bitcoin as a target and Ethereum as a funding cryptocurrency. Our P2W method is designed in a way that reimburses collaborators even in the case of an unsuccessful attack. Interestingly, this actually renders our approach approximately one order of magnitude cheaper than comparable bribing techniques (e.g., the whale attack). We demonstrate the technical feasibility of P2W attacks through publishing all relevant artifacts of this paper, ranging from calculations of success probabilities to a fully functional proof-of-concept implementation, consisting of an Ethereum smart contract and a Python client.

Off-chain protocols (channels) are a promising solution to the scalability and privacy challenges of blockchain payments. Current proposals, however, require synchrony assumptions to preserve the safety of a channel, leaking to an adversary the exact amount of time needed to control the network for a successful attack. In this paper, we introduce Brick, the first payment channel that remains secure under network asynchrony and concurrently provides correct incentives. The core idea is to incorporate the conflict resolution process within the channel by introducing a rational committee of external parties, called wardens. Hence, if a party wants to close a channel unilaterally, it can only get the committee’s approval for the last valid state.

Macroeconomic policy in a blockchain system concerns the algorithm that decides the payment schedule for miners and thus its money mint rate. It governs the amounts, distributions, beneficiaries and conditions required for money supply payments to participants by the system. While most chains today employ simple policies such as a constant amount per block, several cryptocurrencies have sprung up that put forth more interesting policies. As blockchains become a more popular form of money, these policies inevitably are becoming more complex. A chain with a simple policy will often need to switch over to a different policy. Until now, it was believed that such upgrades require a hard fork – after all, they are changing the money supply, a central part of the system, and unupgraded miners cannot validate blocks that deviate from those hard-coded rules. In this paper, we present a mechanism that allows a chain to upgrade from one policy to another through a soft fork. Our proposed mechanism works in today’s Ethereum blockchain without any changes and can support a very generic class of monetary policies that satisfy a few basic bounds. Our construction is presented in the form of a smart contract. We showcase the usefulness of our proposal by describing several interesting applications of policy changes. Notably, we put forth a mechanism that makes Non-Interactive Proofs of Proof-of-Work unbribable, a previously open problem.

Credit allows a lender to loan out surplus capital to a borrower. In the traditional economy, credit bears the risk that the borrower may default on its debt, the lender hence requires upfront collateral from the borrower, plus interest fee payments. Due to the atomicity of blockchain transactions, lenders can offer flash loans, i.e., loans that are only valid within one transaction and must be repaid by the end of that transaction. This concept has lead to a number of interesting attack possibilities, some of which were exploited in February 2020.

State channels are an attractive layer-two solution for improving the throughput and latency of blockchains. They offer optimistic offchain settlement of payments and expedient offchain evolution of smart contracts between multiple parties without any assumptions beyond those of the underlying blockchain. In the case of disputes, or if a party fails to respond, cryptographic evidence collected in the offchain channel is used to settle the last confirmed state onchain, such that in-progress contracts can be continued under mainchain consensus.

The Plaintiff brought a claim for reimbursement of installment payments it had to paid to the Defendant under several marine engine supply contracts. The Defendant disputed the Xiamen Maritime Court’s jurisdiction to hear the case, citing an arbitration clause contained in the contracts between the parties. The Plaintiff argued that the arbitration clause, which required the parties to arbitrate in Sweden, was invalid because it failed to state what law was applicable to the arbitration, named a non-existent entity as the arbitrator, and failed to state other applicable arbitration procedures. The Plaintiff also alleged that the Defendant’s Swedish law experts were unqualified and biased. The Xiamen Maritime Court, applying Swedish law, held that the arbitration clause was valid and enforceable even though no arbitrator had been identified, because the parties had agreed that the country of arbitration was Sweden.

The Plaintiff Jiaolong argued that it fully completed its duties under the terms and requirements of the contract and that the Defendant Huatai did not perform its obligations of payment and therefore breached their contract.

Payment channel networks, and the Lightning Network in particular, seem to offer a solution to the lack of scalability and privacy offered by Bitcoin and other blockchain-based cryptocurrencies. Previous research has focused on the scalability, availability, and crypto-economics of the Lightning Network, but relatively little attention has been paid to exploring the level of privacy it achieves in practice. This paper presents a thorough analysis of the privacy offered by the Lightning Network, by presenting several attacks that exploit publicly available information about the network in order to learn information that is designed to be kept secret, such as how many coins a node has available or who the sender and recipient are in a payment routed through the network.

The Plaintiff freight forwarder held entitled to recover some but not all of claimed amounts advanced to carriers on behalf of defendants, there being inadequate proof that all payments had been authorized by defendants.

In this paper, we introduce FPPW, a new payment channel with watchtower scheme for Bitcoin. This new scheme provides fairness w.r.t. all channel participants including both channel parties and the watchtower. It means that the funds of any honest channel participant are safe even assuming that other two channel participants are corrupted and/or collude with each other. Furthermore, the watchtower in FPPW learns no information about the off-chain transactions and hence FPPW provides privacy against the watchtower. As a byproduct, we also define the coverage of a watchtower scheme, that is the total capacity of channels that a watchtower can cover on a scale of 0 to 1, and show that FPPW’s coverage is higher than those of PISA and Cerberus. The scheme can be implemented without any update in Bitcoin script.

The Plaintiff, a cargo insurer, brought this action against the Defendant, a multimodal carrier, seeking payment for water damage to third party insured’s industrial automatic control equipment. The Plaintiff argued that the Defendant’s failure to provide an adequate shipping container for the equipment coupled with evidence of sea and freshwater intrusion proved that Defendant was liable for the damage.

In smart urban settings, all devices and service providers monitor, collect and exchange data whilst device producers and service providers store, distribute, analyse and re-use data on a grand scale. If firms would like to combine such data, they need to give each other access by sharing, trading or pooling the data. On the one hand, the industry-wide pooling of data could increase the efficiency of certain services and contribute to the innovation of other services, e.g. whole transport networks that are available on one platform, or Mobility as a Service (MaaS). On the other hand, firms that pool business data may use the data not to advance their services or products but to collude, to exclude competitors or to abuse their market position. Indeed, by combining their data and collaborating they can gain market power and hence the ability to violate competition law. Platforms can also hoard data and design the data architecture so as to become system leaders in vertical value chains, exclusively obtaining all data from various sources and creating a silo or ecosystem. This chapter will discuss a new platform configuration regarding transport services. The platform is being developed and discussed according to the notion of MaaS. MaaS is a new transport paradigm that integrates existing and new mobility services as well as public and private transport services into one single digital platform, providing customised door-to-door transport and offering personalised trip planning and payment options. The development of integrated multimodal information systems and integrated payment solutions has enabled the MaaS concept to unfold. We will analyse the MaaS concept from a competition law perspective, asking whether the concept might be in violation of EU Competition Law, specifically Arts. 101 and 102 TFEU.

Insurance companies are often considered the origin of MCOs. Even though this is true regarding the revival of managed care since the mid-1970s, MCOs in the United States originated in the form of prepaid group practices (PGP) connected to the assumption of risks by service providers in the 1920s. In rural areas physician group practices offered to let residents use the services of the group practice without restrictions in return for monthly or annual payments. Services outside of the group practice were not covered.

This paper is devoted to the study of transaction fees in massively replicated open blockchain systems. In such systems, like Bitcoin, a snapshot of current state required for the validation of transactions is being held in the memory, which eventually becomes a scarce resource. Uncontrolled state growth can lead to security issues. We propose a modification of a transaction fee scheme based on how much additional space will be needed for the objects created as a result of transaction processing and for how long will they live in the state. We also work out the way to combine fees charged for different resources spent (bandwidth, random-access state memory, processor cycles) in a composite fee and demonstrate consistency of the approach by analyzing the statistics from Ethereum network. We show a possible implementation for state-related fee in a form of regular payments to miners.

We present three smart contracts that allow a briber to fairly exchange bribes to miners who pursue a mining strategy benefiting the briber. The first contract, CensorshipCon, highlights that Ethereum’s uncle block reward policy can directly subsidise the cost of bribing miners. The second contract, HistoryRevisionCon, rewards miners via an in-band payment for reversing transactions or enforcing a new state of another contract. The third contract, GoldfingerCon, rewards miners in one cryptocurrency for reducing the utility of another cryptocurrency. This work is motivated by the need to understand the extent to which smart contracts can impact the incentive mechanisms involved in Nakamoto-style consensus protocols.

A promising type of innovative business models for the machinery and plant engineering industry are subscription models. In an industrial context, subscription models are enabled by novel opportunities due to ongoing digitization and Industrie 4.0. Customers receive a regular delivery of performance in terms of a product-service system in return for a continuous payment of a subscription fee. Prerequisite for an efficient subscription model is the interaction of several industrial players with in-depth knowledge in a network, in which every player derives its benefit from a low-risk long-term business. Before implementing this new business model, companies need to assess the potential risks and rewards of the subscription model for their particular application. This paper presents a methodology for the evaluation of risks, rewards and chances for stakeholders in a subscription ecosystem. Furthermore, it can be used as an appropriate tool for designing efficient, subscription-based partner networks and attractive value propositions for machinery and plant engineering companies.

The two main challenges in deploying real world secure poker protocols lie in enforcing the distribution of rewards and dealing with misbehaving/aborting parties. Using recent advances in cryptocurrencies and blockchain techniques, Kumaresan et al. (CCS 2015) and Bentov et al. (ASIACRYPT 2017) were able to solve those problems for the general case of secure multiparty computation. However, in the specific case of secure poker, they leave major open problems in terms of efficiency and security. This work tackles these problems by presenting the first full-fledged simulation-based security definition for secure poker and the first fully-simulatable secure poker protocol that provably realizes such a security definition. Our protocol provably enforces rewards distribution and penalties for misbehaving parties, while achieving efficiency comparable to previous tailor-made poker protocols, which do not have formal security proofs and rewards/penalties enforcement. Moreover, our protocol achieves reduced on-chain storage requirements for the penalties and rewards enforcement mechanism.