The reward-complexity trade-off in schizophrenia

Action selection requires a policy that maps states of the world to a distribution over actions. The amount of memory needed to specify the policy (the policy complexity) increases with the state-dependence of the policy. If there is a capacity limit for policy complexity, then there will also be a trade-off between reward and complexity, since some reward will need to be sacrificed in order to satisfy the capacity constraint. This paper empirically characterizes the trade-off between reward and complexity for both schizophrenia patients and healthy controls. Schizophrenia patients adopt lower complexity policies on average, and these policies are more strongly biased away from the optimal reward-complexity trade-off curve compared to healthy controls. How-ever, healthy controls are also biased away from the optimal trade-off curve, and both groups appear to lie on the same empirical trade-off curve. We explain these findings using a cost-sensitive actor-critic model. Our empirical and theoretical results shed new light on cognitive effort abnormalities in schizophrenia.

The Testing of Empirical Trade Off Theory in Determining Value of the Firm in Manufacturing Industries in Indonesia

This research aims to determine the application of trade off theory in determining the value of the firm by observing the factors of institutional ownership structure, liquidity and profitability that affect the capital structure and test the differences in capital structure in LQ-45 firms. The results showed that the independent variables jointly had a significant effect on the dependent variable of 15.90% with the fixed effect model as a fit model for measuring capital structure. The results showed that the structure of institutional ownership and profitability had a significant effect on capital structure variables, while the current ratio had no significant effect on capital structure variables. This research found that firms with high Institutional Ownership Structure (KPI) can increase external funding so that the capital structure is higher. Liquidity (current ratio) does not affect the capital structure (DER). Low profitability (return on equity) will increase the capital structure (DER), because firms need external funding to overcome their profitability. The results of this research indicate that there is no difference between the capital structure of firms that have high value and low value. Thus, the results of the research do not support the trade off theory in capital structure decisions in manufacturing firms in Indonesia.

Gravity Models and Empirical Trade

The gravity model of international trade states that the volume of trade between two countries is proportional to their economic mass and a measure of their relative trade frictions. Perhaps because of its intuitive appeal, the gravity model has been the workhorse model of international trade for more than 50 years. While the initial empirical work using the gravity model lacked sound theoretical underpinnings, the theoretical developments have highlighted how a gravity-like specification can be derived from many models with varying assumptions about preferences, technology, and market structure. Along the strengthening of the theoretical roots of the gravity model, the way in which it is estimated has also evolved significantly since the start of the new millennium. Depending on the exact characteristics of regression, different estimation methods should be used to estimate the gravity model.

Political Trade-Offs: Democracy and Governance in a Changing World

The investigation of trade-offs in political science receives only limited attention, although many scholars acknowledge the importance of trade-offs across a variety of different areas. A systematic and comprehensive examination of the topic is missing. This thematic issue of <em>Politics and Governance</em> sheds light on this research deficit by providing a holistic but also an integrative view on trade-offs in the political realm for the first time. Researchers of trade-offs from different political areas present and discuss their findings, and promote a fruitful exchange, which overcomes the current isolation of the approaches. They consider the theoretical and methodological questions as well as the identification of empirical trade-offs. Furthermore, they provide insights into the possibility to balance trade-offs and strategies, which could help actors to find such compromises.

On the Complexity and Typology of Inflectional Morphological Systems

We quantify the linguistic complexity of different languages’ morphological systems. We verify that there is a statistically significant empirical trade-off between paradigm size and irregularity: A language’s inflectional paradigms may be either large in size or highly irregular, but never both. We define a new measure of paradigm irregularity based on the conditional entropy of the surface realization of a paradigm— how hard it is to jointly predict all the word forms in a paradigm from the lemma. We estimate irregularity by training a predictive model. Our measurements are taken on large morphological paradigms from 36 typologically diverse languages.

Maximum-Entropy Tools for Economic Fitness and Complexity

The concepts of economic fitness and complexity, based on iterative and interdependent definitions of the quality of exporting countries and exported products, have led to novel insights into the dynamics of production and trade. A key step in the calculation of these quantities is the preliminary identification of statistically relevant country-product pairs.In this paper, we propose a method that could improve the current practice of filtering based on the revealed comparative advantage, by employing the maximum-entropy principle to construct an unbiased link weight probability distribution that, unlike the traditional thresholding method, allows for the statistical assessment of empirical trade volumes. The result is an adjusted geometric distribution for trade links that refines the revealed comparative advantage approach. This allows us to define the statistical significance of each trade link weight, leading to statistically supported trade link filtering decisions. Using this statistically justified filtering method, we have obtained results that are similar in nature to those that were found without this method, even though there are significant deviations in the details. In addition, the statistical information thus obtained on each trade link allows us to perform a spectral analysis of the export portfolio of individual economies.

Managing Communication Costs under Temporal Uncertainty

In multi-agent temporal planning, individual agents cannot know a priori when other agents will execute their actions and so treat those actions as uncertain. Only when others communicate the results of their actions is that uncertainty resolved. If a full communication protocol is specified ahead of time, then delay controllability can be used to assess the feasibility of the temporal plan. However, agents often have flexibility in choosing when to communicate the results of their action. In this paper, we address the question of how to choose communication protocols that guarantee the feasibility of the original temporal plan subject to some cost associated with that communication. To do so, we introduce a means of extracting delay controllability conflicts and show how we can use these conflicts to more efficiently guide our search. We then present three conflict-directed search algorithms and explore the theoretical and empirical trade-offs between the different approaches.

Retrospectives: Adam Smith's Discovery of Trade Gravity

The gravity equation is a current workhorse of empirical trade theory. It is generally acknowledged that this theory, which relates the extent of trade between countries to their respective sizes, distances, and relative trade barriers, was first developed by Jan Tinbergen in 1962. Acceptance of the gravity model as part of the discipline's core was limited by its scant theoretical foundation for the first 40 years of its existence. This paper finds that a theory of trade gravity was first developed by Adam Smith in The Wealth of Nations. Moreover, it is shown that Smith's statement of a proportional relation between economic size and distance came about as an application of his general theory of differential capital productivity in different economic sectors, and his elaboration of a theory of the gains from trade originated by David Hume. It is further shown that Smith had an explanation of the size of border affects in trade volumes, and a gravity theory of trade restrictions.

Export Credit Insurance and Export Performance: An Empirical Gravity Analysis for Turkey

The paper attempts to find out how far Turkey’s official export credit agency, Turk Eximbank, foster export of Turkey during the years of 2000-2015 by employing an empirical trade gravity equation. We estimate different panel gravity regressions for 212 countries for the period of 16 years and the results reveal that a change in export credit insurance positively affect Turkish export, assuming other independent variables are held constant. After applying several post estimation tests we used fixed effect panel specification as the main estimation. In order to allow comparison we also run clustered, robust OLS. Poisson fixed effect (Poisson) and Poisson Pseudo maximum likelihood estimations (PPML) are also estimated to allow for zero trade values in dependent variable in its level. Our analysis also shows that there are significant individual and time effects in panel data structure. Our estimate of different panel gravity regressions for 212 countries and 16 years revealed that increasing export insurance will positively affect Turkish export.

Total Factor Productivity and Most Favored Nations Tariffs: Evidence from Croatia

One of the most important topics in empirical trade research is the link between productivity and trade liberalization. In this paper we will focus on the effect of MFN tariffs in the total factor productivity of Croatian firms over the period 2003-2012. This period is characterized by an increased openness toward European Union for Croatian firms. The aim of this paper is to present evidence on the negative link between productivity and tariffs by using the Levinsohn and Petrin (2003) method to estimate productivity of firms. Then we will use TFP as a dependent variable for firm characteristics and trade policy indicator (MFN tariffs). The results are in line with most other studies, confirming the negative relationship between TFP and tariffs. The results show that exporting firms have a higher productivity than non-exporting. We also conclude that up to a certain age productivity increases and then decreases.