scholarly journals On the Value of Penalties in Time-Inconsistent Planning

2021 ◽  
Vol 9 (3) ◽  
pp. 1-18
Author(s):  
Susanne Albers ◽  
Dennis Kraft
Keyword(s):  
Approximation Algorithm ◽  
Combinatorial Problem ◽  
Task Graph ◽  
Np Hard ◽  
Present Bias ◽  
Time Inconsistent ◽  
Commitment Devices ◽  
The Impact ◽  
Over Time ◽  
Commitment Device

People tend to behave inconsistently over time due to an inherent present bias. As this may impair performance, social and economic settings need to be adapted accordingly. Common tools to reduce the impact of time-inconsistent behavior are penalties and prohibition. Such tools are called commitment devices. In recent work Kleinberg and Oren [6, 7] connect the design of prohibition-based commitment devices to a combinatorial problem in which edges are removed from a task graph G with n nodes. However, this problem is NP-hard to approximate within a ratio less than √n/3 [2]. To address this issue, we propose a penalty-based commitment device that does not delete edges but raises their cost. The benefits of our approach are twofold. On the conceptual side, we show that penalties are up to 1/β times more efficient than prohibition, where β ϵ (0,1] parameterizes the present bias. On the computational side, we significantly improve approximability by presenting a 2-approximation algorithm for allocating the penalties. To complement this result, we prove that optimal penalties are NP-hard to approximate within a ratio of 1.08192.

APPROXIMATING THE JOINT REPLENISHMENT PROBLEM WITH DEADLINES

2009 ◽  
Vol 01 (02) ◽  
pp. 153-173 ◽  
Author(s):  
TIM NONNER ◽  
ALEXANDER SOUZA
Keyword(s):  
Approximation Algorithm ◽  
Cost Functions ◽  
Np Hard ◽  
Joint Replenishment ◽  
Joint Replenishment Problem ◽  
Linear Delay ◽  
Delay Cost ◽  
Two Stages ◽  
Special Case ◽  
Over Time

The objective of the classical Joint Replenishment Problem (JRP) is to minimize ordering costs by combining orders in two stages, first at some retailers, and then at a warehouse. These orders are needed to satisfy demands that appear over time at the retailers. We investigate the natural special case that each demand has a deadline until when it needs to be satisfied. For this case, we present a randomized 5/3-approximation algorithm. We moreover prove that JRP with deadlines is APX-hard. Finally, we extend the known hardness results by showing that JRP with linear delay cost functions is NP-hard, even if each retailer has to satisfy only three demands.

scholarly journals Time-Inconsistent Planning: Simple Motivation Is Hard to Find

2020 ◽  
Vol 34 (06) ◽  
pp. 9843-9850
Author(s):  
Fedor V. Fomin ◽  
Torstein J. F. Strømme
Keyword(s):  
Polynomial Algorithm ◽  
Time Inconsistency ◽  
Structural Parameter ◽  
Reasonable Assumption ◽  
Task Graph ◽  
Present Moment ◽  
Graph Theoretic ◽  
Present Bias ◽  
Np Complete ◽  
Time Inconsistent

People sometimes act differently when making decisions affecting the present moment versus decisions affecting the future only. This is referred to as time-inconsistent behaviour, and can be modeled as agents exhibiting present bias. A resulting phenomenon is abandonment, which is when an agent initially pursues a task, but ultimately gives up before reaping the rewards. With the introduction of the graph-theoretic time-inconsistent planning model due to Kleinberg and Oren, it has been possible to investigate the computational complexity of how a task designer best can support a present-biased agent in completing the task. In this paper, we study the complexity of finding a choice reduction for the agent; that is, how to remove edges and vertices from the task graph such that a present-biased agent will remain motivated to reach his target even for a limited reward. While this problem is NP-complete in general, this is not necessarily true for instances which occur in practice, or for solutions which are of interest to task designers. For instance, a task designer may desire to find the best task graph which is not too complicated. We therefore investigate the problem of finding simple motivating subgraphs. These are structures where the agent will modify his plan at most k times along the way. We quantify this simplicity in the time-inconsistency model as a structural parameter: The number of branching vertices (vertices with out-degree at least 2) in a minimal motivating subgraph. Our results are as follows: We give a linear algorithm for finding an optimal motivating path, i. e. when k = 0. On the negative side, we show that finding a simple motivating subgraph is NP-complete even if we allow only a single branching vertex — revealing that simple motivating subgraphs are indeed hard to find. However, we give a pseudo-polynomial algorithm for the case when k is fixed and edge weights are rationals, which might be a reasonable assumption in practice.

COMMITMENT DEVICES IN MARRIAGE FOR SAVINGS: EVIDENCE FROM JAPAN

2019 ◽  
pp. 1950038
Author(s):  
WATARU KUREISHI ◽  
MIDORI WAKABAYASHI
Keyword(s):  
Household Savings ◽  
Micro Data ◽  
Cross Sectional ◽  
Cross Sectional Analysis ◽  
Married Individuals ◽  
Time Inconsistent ◽  
Sectional Analysis ◽  
Commitment Devices ◽  
Commitment Device

We empirically test the hypothesis that, for married individuals with time-inconsistent preferences, leaving the management of family budgets to their spouse functions as a commitment device for savings. We conduct a cross-sectional analysis based on the micro-data of married Japanese couples obtained from waves 2009 and 2010 of Osaka University’s Preference Parameters Study. Our results show that when wives have time-inconsistent preferences, their household savings are more likely to go as planned if they leave household budgets to their husbands in comparison to when they make these decisions themselves. However, time-inconsistent individuals do not actively use leaving the management of family budgets to their spouse as a commitment device for savings. Considering these, we conclude that individuals do not recognize the benefits of leaving the management of family budgets to their spouse, but it can work as a commitment device.

The Therapist’s Reaction to a Patient’s Suicide

Crisis ◽  
2011 ◽  
Vol 32 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Friedrich Martin Wurst ◽  
Isabella Kunz ◽  
Gregory Skipper ◽  
Manfred Wolfersdorf ◽  
Karl H. Beine ◽  
...  
Keyword(s):  
Emotional Responses ◽  
Well Being ◽  
Emotional Reaction ◽  
Emotional Reactions ◽  
Analog Scale ◽  
General Hospitals ◽  
Item Questionnaire ◽  
Retrospective Nature ◽  
The Impact ◽  
Over Time

Background: A substantial proportion of therapists experience the loss of a patient to suicide at some point during their professional life. Aims: To assess (1) the impact of a patient’s suicide on therapists distress and well-being over time, (2) which factors contribute to the reaction, and (3) which subgroup might need special interventions in the aftermath of suicide. Methods: A 63-item questionnaire was sent to all 185 Psychiatric Clinics at General Hospitals in Germany. The emotional reaction of therapists to patient’s suicide was measured immediately, after 2 weeks, and after 6 months. Results: Three out of ten therapists suffer from severe distress after a patients’ suicide. The item “overall distress” immediately after the suicide predicts emotional reactions and changes in behavior. The emotional responses immediately after the suicide explained 43.5% of the variance of total distress in a regression analysis. Limitations: The retrospective nature of the study is its primary limitation. Conclusions: Our data suggest that identifying the severely distressed subgroup could be done using a visual analog scale for overall distress. As a consequence, more specific and intensified help could be provided to these professionals.

Has Aid Helped in Pakistan?

1997 ◽  
Vol 36 (4II) ◽  
pp. 947-957 ◽  
Author(s):  
Shahrukh Rafi Khan
Keyword(s):  
Economic Growth ◽  
Negative Impact ◽  
Negative Association ◽  
Causal Impact ◽  
The Impact ◽  
Over Time

This paper has a two-fold objective: first, to examine the terms on which Pakistan receives aid and whether its debt situation is sustainable, and second, to examine the impact of aid and debt on economic growth. It is found that there is little encouraging that can be said about how the terms on which Pakistan has received aid over time have changed, and its current debt situation is not sustainable. Also reported is the analysis done elsewhere which shows that aid has a negative (Granger) causal impact on GDP, and aid has a robust negative impact on economic growth after controlling for supplyside shocks. We provide various reasons for this negative association.

The Role of Vascular Aging in Atherosclerotic Plaque Development and Vulnerability

2019 ◽  
Vol 25 (29) ◽  
pp. 3098-3111 ◽  
Author(s):  
Luca Liberale ◽  
Giovanni G. Camici
Keyword(s):  
Atherosclerotic Plaque ◽  
Molecular Mechanisms ◽  
Driving Forces ◽  
Plaque Burden ◽  
Vascular Aging ◽  
Age Related ◽  
Plaque Development ◽  
Increased Risk ◽  
The Impact ◽  
Over Time

Background: The ongoing demographical shift is leading to an unprecedented aging of the population. As a consequence, the prevalence of age-related diseases, such as atherosclerosis and its thrombotic complications is set to increase in the near future. Endothelial dysfunction and vascular stiffening characterize arterial aging and set the stage for the development of cardiovascular diseases. Atherosclerotic plaques evolve over time, the extent to which these changes might affect their stability and predispose to sudden complications remains to be determined. Recent advances in imaging technology will allow for longitudinal prospective studies following the progression of plaque burden aimed at better characterizing changes over time associated with plaque stability or rupture. Oxidative stress and inflammation, firmly established driving forces of age-related CV dysfunction, also play an important role in atherosclerotic plaque destabilization and rupture. Several genes involved in lifespan determination are known regulator of redox cellular balance and pre-clinical evidence underlines their pathophysiological roles in age-related cardiovascular dysfunction and atherosclerosis. Objective: The aim of this narrative review is to examine the impact of aging on arterial function and atherosclerotic plaque development. Furthermore, we report how molecular mechanisms of vascular aging might regulate age-related plaque modifications and how this may help to identify novel therapeutic targets to attenuate the increased risk of CV disease in elderly people.

Conclusion

2018 ◽  
Author(s):  
Manuel Fröhlich ◽  
Abiodun Williams
Keyword(s):  
Security Council ◽  
International Context ◽  
Peace And Security ◽  
Executive Action ◽  
Trends Over Time ◽  
The Impact ◽  
Over Time ◽  
The Way ◽  
Guiding Questions

The Conclusion returns to the guiding questions introduced in the Introduction, looking at the way in which the book’s chapters answered them. As such, it identifies recurring themes, experiences, structures, motives, and trends over time. By summarizing the result of the chapters’ research into the interaction between the Secretaries-General and the Security Council, some lessons are identified on the changing calculus of appointments, the conditions and relevance of the international context, the impact of different personalities in that interaction, the changes in agenda and composition of the Council as well as different formats of interaction and different challenges to be met in the realm of peace and security, administration, and reform, as well as concepts and norms. Taken together, they also illustrate the potential and limitations of UN executive action.

Understanding Rising Income Inequality and Stagnating Ordinary Living Standards in Germany

2018 ◽  
Author(s):  
Gerhard Bosch ◽  
Thorsten Kalina
Keyword(s):  
Income Inequality ◽  
Labour Market ◽  
Economic Crisis ◽  
Household Income ◽  
Wage Bargaining ◽  
Living Standards ◽  
Social Model ◽  
Real Wages ◽  
The Impact ◽  
Over Time

This chapter describes how inequality and real incomes have evolved in Germany through the period from the 1980s, through reunification, up to the economic Crisis and its aftermath. It brings out how reunification was associated with a prolonged stagnation in real wages. It emphasizes how the distinctive German structures for wage bargaining were eroded over time, and the labour market and tax/transfer reforms of the late 1990s-early/mid-2000s led to increasing dualization in the labour market. The consequence was a marked increase in household income inequality, which went together with wage stagnation for much of the 1990s and subsequently. Coordination between government, employers, and unions still sufficed to avoid the impact the economic Crisis had on unemployment elsewhere, but the German social model has been altered fundamentally over the period

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