On the estimation of Tsallis entropy and a novel information measure based on its properties

This letter explores a plug-in estimator of second-order Tsallis entropy based on Kernel Density Estimation (KDE) and its implicit regularization process. First, it is shown that the expected value of the estimator corresponds to the entropy of an Additive White Gaussian Noise (AWGN) model. Then, we prove various relevant properties of the Tsallis entropy: It is monotonically non-decreasing under random variables addition, its derivative with respect to the Gaussian noise power is monotonically non-increasing, and it is concave in the additive noise power. From these, we derive an information metric that provides an alternative to the strategy of regularization.This work was supported in part by the Spanish Ministry of Science and Innovation project RODIN under Grant PID2019-105717RB-C22, in part by Generalitat de Catalunya under Grant 2021 SGR 01033, in part by Fellowship 2019 FI 00620 and Fellowship 2023 FI “Joan Oró” 00050 by the Generalitat de Catalunya and the European Social Fund, and in part by Fellowship 2022 FPI-UPC 028 by the Universitat Politècnica de Catalunya and Banc de Santander. The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Giuseppe Thadeu Freitas de AbreuPeer ReviewedPostprint (published version

Defining typologies of universities through a DEA-MDS analysis: An institutional characterization for formative evaluation purposes

Universities are organizational structures with individual activity mixes or strategies that lead to different performance levels by mission. Evaluation techniques based on performance indicators or rankings risk rewarding just a specific type of university and undermining university diversification: they usually introduce homogenizing pressures and risk displacing university objectives¿neglecting their socio-economic contribution and focusing on succeeding on the evaluation system. In this study, we propose an alternative evaluation method that overcomes these limitations. We produce a multidimensional descriptive classification of universities into typologies, while analysing the relation between their institutional factors (characteristics) and their (technical) efficiency performance from a descriptive perspective. To do so we apply bootstrap data envelopment analysis (DEA) and multidimensional scaling analysis (MDS), performing a so-called DEA-MDS analysis on data n the Spanish university system, and unlike previous studies, we include data on an important dimension of the third mission of universities (specifically knowledge transfer, KT) in their characterization. We identify six types of (homogeneous) universities. Results indicate that to be fairly efficient, universities may focus on teaching, KT, or overall efficiency but always have to fairly perform in research. Additionally, results confirm the relevance of the third mission as a source of institutional diversity in higher education. This approach could be used to address an alternative evaluation methodology for higher education institutions with formative purposes, evaluating universities according to their unique characteristics for the improvement of HE systems

Context-aware lossless and lossy compression of radio frequency signals

We propose an algorithm based on linear prediction that can perform both the lossless and near-lossless compression of RF signals. The proposed algorithm is coupled with two signal detection methods to determine the presence of relevant signals and apply varying levels of loss as needed. The first method uses spectrum sensing techniques, while the second one takes advantage of the error computed in each iteration of the Levinson–Durbin algorithm. These algorithms have been integrated as a new pre-processing stage into FAPEC, a data compressor first designed for space missions. We test the lossless algorithm using two different datasets. The first one was obtained from OPS-SAT, an ESA CubeSat, while the second one was obtained using a SDRplay RSPdx in Barcelona, Spain. The results show that our approach achieves compression ratios that are 23% better than gzip (on average) and very similar to those of FLAC, but at higher speeds. We also assess the performance of our signal detectors using the second dataset. We show that high ratios can be achieved thanks to the lossy compression of the segments without any relevant signal.This work was (partially) funded by the European Space Agency (ESA) Contract No. 4000137290, the Spanish Ministry of Science and Innovation projects PID2019-105717RB-C22 (RODIN) and PID2021-122842OB-C21, the ERDF (a way of making Europe) by the European Union, the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia María de Maeztu) through grant CEX2019-000918-M, grant 2021 SGR 1033 by Generalitat de Catalunya (AGAUR), and fellowship FPI-UPC 2022 by Universitat Politècnica de Catalunya and Banc de Santander.Postprint (published version

The twilight years of the Spanish cajas: governance, risk behavior and growth on the eve of the crisis

El sistema financiero español se ha visto gravemente afectado por la crisis de 2007–2008. En particular, las Cajas de Ahorros Españolas, entidades financieras con una naturaleza particular que llegaron a ostentar la mitad del sistema financiero, prácticamente han desaparecido a finales de 2012. Ciertamente este colapso fue precedido por otros en algunos países, pero estamos convencidos de que podemos extraer algunas lecciones importantes y novedosas gracias a ciertos elementos diferenciadores del caso español. En primer lugar, ya pesar de la ausencia de propietarios, las Cajas tenían una aparentemente sólida situación financiera y un crecimiento constante antes de la crisis. De hecho, su particular estructura de gobierno les permitió ganar cuota de mercado, ya desde los años 80, respecto los bancos comerciales, organizaciones muy competitivas a nivel internacional y sujetos a los tradicionales mecanismos de mercado de control corporativo. En segundo lugar, parece que la competencia en los mercados no fue suficiente para disciplinar el comportamiento de las Cajas durante los años de boom. De hecho, la presencia de una fuerte competencia animó a muchas Cajas (curiosamente con algunas excepciones relevantes) a involucrarse en políticas muy expansivas e inversiones cuestionables, exigiendo recursos mucho más allá de sus posibilidades internas. De cualquier manera, muchas Cajas compitieron y comenzaron a comportarse como los grandes bancos comerciales, sin tener en cuenta sus limitaciones para recaudar nuevo capital en los mercados. Como resultado, de las 45 Cajas existentes en 2008, sólo 12 de ellas quedaron en pie a finales de 2012. Además, en la práctica se han transformado en bancos comerciales, y su número final será todavía más bajo, a la espera de algunos movimientos adicionales aún por venir. ¿Qué tenían de especial las Cajas? ¿Qué sucedió con ellas durante la crisis? ¿Y por qué? El objetivo principal de esta Tesis es lograr una mejor comprensión de la naturaleza específica de las Cajas, el análisis de su comportamiento y su performance, y compararlas con sus competidores más directos, los bancos comerciales españoles, usando un período suficientemente largo que incluya tanto los años de auge como los de crisis. Creemos que este enfoque nos ayudará a responder a las preguntas antes mencionadas, añadiendo nuevos elementos de discusión a un debate que no ha sido lo suficientemente extenso. El debate sobre la caída de las Cajas rara vez ha ido más allá del ámbito político y de los medios, donde argumentos demasiado simplificados como la politización de las mismas han servido para señalar la fuente del problema. La falta de trabajo académico para analizar este tema tan relevante de manera profunda es notable. En consecuencia, el propósito de esta Tesis es analizar las Cajas bajo distintos ángulos bien diferenciados, aunque relacionados, con el fin de comprender al menos parte de la naturaleza subyacente de las grandes dificultades que han atravesado y su posterior desaparición. Consideramos que un enfoque diferenciado ante un problema complejo nos permitirá una interpretación más amplia e innovadora del mismo, así como la obtención de conclusiones realmente útiles.The Spanish financial system has been severely affected by the 2007–2008 crisis. In particular, the Spanish savings banks (Cajas de Ahorros, or Cajas), an ownerless type of bank that used to constitute half of the financial system, have practically disappeared by the end of 2012. Certainly this collapse has been preceded by large failures in other countries’ financial systems, but we are convinced that some important and novel lessons can still be extracted from the differential elements present in the Spanish case. First of all, and in spite of their lack of owners, Spanish savings banks were apparently in great financial condition and growing steadily before the last financial crisis. In fact, their governance structure allowed them to gain market share, since the 80’s, from commercial banks, which were big and internationally competitive organizations subject to the usual market mechanisms for corporate control. Second, although market competition was in place, it seems that it was not enough to discipline the Cajas' behaviour in those boom years. In fact, the presence of an intense competition encouraged many of the Cajas (interestingly, with some important exceptions) to get involved in very expansive policies and questionable investments, demanding resources much beyond their own internal possibilities. Somehow, many savings banks competed and started to behave like large commercial banks, disregarding their limitations to raise new capital from the markets. As a result, from the original 45 Savings banks existing in 2008, only 12 of them remained by the end of 2012. On top of that, they have been transformed into commercial banks and their final number will be even lower, through mergers, with some additional moves still to come. What was special about the Cajas? What did it happen to them during the crisis? And why? The main goal of this Thesis is to achieve a better understanding of the particular nature of the Cajas, analyzing their behaviour and performance, and compare this with their most direct competitors (i.e., the Spanish commercial banks) using a long enough period that includes both a boom period and the years of the crisis. We believe that such approach will help us to answer the questions mentioned above, adding new elements to a debate that has been really extensive but not exhausted. Nonetheless, a debate on the Cajas fall has rarely gone beyond the political and public media spheres, where simple arguments such as the politicization have been pointed out as the unique source of the problem. The lack of academic work analyzing this relevant topic in an in-depth manner is noticeable. Thus, the purpose of this Thesis is to analyze the Cajas under several although related (and quite differentiated) angles in order to grasp the underlying nature of their large financial distress and later disappearance. We consider that this differentiated approach to a complex problem will allow us a broader and more innovative interpretation of the different events and behaviours involved

Governance, human capital and politicization of Spanish banks

Before the 2007 financial crisis, Spanish savings banks (Cajas) and commercial banks had shared, almost equally, the Spanish market for years. By 2012, the stakeholder-oriented Cajas had disappeared. We study if these different outcomes of Cajas and commercial banks respond to different ownership structures, governance practices and top managers' human capital. Most of the previous debate has focused on the political affiliation of Cajas' managers. We contribute to the debate by using broader measures of banks' performance and by manually collecting chairman's human capital (through proxies such as chairman's experience, education, and political affiliation) for both bank types. We find that commercial banks took more risks in pre-crisis years and showed better risk-management than Cajas during the crisis. We find no evidence of the influence of chairman's political affiliation on banks' performance, but chairman's firm experience and certain levels of education did have an impact on banks' performance, showing that managers' human capital deserves more attention. Finally, we analyse deeper Cajas-stakeholders' participation, and while the presence of politicised seats in the governing bodies have no significant effects, larger employee participation or depositors' involvement could have helped to improve the resilience of these stakeholder organisations during the crisis

The twilight years of the Spanish cajas: governance, risk behavior and growth on the eve of the crisis

El sistema financiero español se ha visto gravemente afectado por la crisis de 2007-2008. En particular, las Cajas de Ahorros Españolas, entidades financieras con una naturaleza particular que llegaron a ostentar la mitad del sistema financiero, prácticamente han desaparecido a finales de 2012. Ciertamente este colapso fue precedido por otros en algunos países, pero estamos convencidos de que podemos extraer algunas lecciones importantes y novedosas gracias a ciertos elementos diferenciadores del caso español. En primer lugar, ya pesar de la ausencia de propietarios, las Cajas tenían una aparentemente sólida situación financiera y un crecimiento constante antes de la crisis. De hecho, su particular estructura de gobierno les permitió ganar cuota de mercado, ya desde los años 80, respecto los bancos comerciales, organizaciones muy competitivas a nivel internacional y sujetos a los tradicionales mecanismos de mercado de control corporativo. En segundo lugar, parece que la competencia en los mercados no fue suficiente para disciplinar el comportamiento de las Cajas durante los años de boom. De hecho, la presencia de una fuerte competencia animó a muchas Cajas (curiosamente con algunas excepciones relevantes) a involucrarse en políticas muy expansivas e inversiones cuestionables, exigiendo recursos mucho más allá de sus posibilidades internas. De cualquier manera, muchas Cajas compitieron y comenzaron a comportarse como los grandes bancos comerciales, sin tener en cuenta sus limitaciones para recaudar nuevo capital en los mercados. Como resultado, de las 45 Cajas existentes en 2008, sólo 12 de ellas quedaron en pie a finales de 2012. Además, en la práctica se han transformado en bancos comerciales, y su número final será todavía más bajo, a la espera de algunos movimientos adicionales aún por venir. ¿Qué tenían de especial las Cajas? ¿Qué sucedió con ellas durante la crisis? ¿Y por qué? El objetivo principal de esta Tesis es lograr una mejor comprensión de la naturaleza específica de las Cajas, el análisis de su comportamiento y su performance, y compararlas con sus competidores más directos, los bancos comerciales españoles, usando un período suficientemente largo que incluya tanto los años de auge como los de crisis. Creemos que este enfoque nos ayudará a responder a las preguntas antes mencionadas, añadiendo nuevos elementos de discusión a un debate que no ha sido lo suficientemente extenso. El debate sobre la caída de las Cajas rara vez ha ido más allá del ámbito político y de los medios, donde argumentos demasiado simplificados como la politización de las mismas han servido para señalar la fuente del problema. La falta de trabajo académico para analizar este tema tan relevante de manera profunda es notable. En consecuencia, el propósito de esta Tesis es analizar las Cajas bajo distintos ángulos bien diferenciados, aunque relacionados, con el fin de comprender al menos parte de la naturaleza subyacente de las grandes dificultades que han atravesado y su posterior desaparición. Consideramos que un enfoque diferenciado ante un problema complejo nos permitirá una interpretación más amplia e innovadora del mismo, así como la obtención de conclusiones realmente útiles.The Spanish financial system has been severely affected by the 2007-2008 crisis. In particular, the Spanish savings banks (Cajas de Ahorros, or Cajas), an ownerless type of bank that used to constitute half of the financial system, have practically disappeared by the end of 2012. Certainly this collapse has been preceded by large failures in other countries' financial systems, but we are convinced that some important and novel lessons can still be extracted from the differential elements present in the Spanish case. First of all, and in spite of their lack of owners, Spanish savings banks were apparently in great financial condition and growing steadily before the last financial crisis. In fact, their governance structure allowed them to gain market share, since the 80's, from commercial banks, which were big and internationally competitive organizations subject to the usual market mechanisms for corporate control. Second, although market competition was in place, it seems that it was not enough to discipline the Cajas' behaviour in those boom years. In fact, the presence of an intense competition encouraged many of the Cajas (interestingly, with some important exceptions) to get involved in very expansive policies and questionable investments, demanding resources much beyond their own internal possibilities. Somehow, many savings banks competed and started to behave like large commercial banks, disregarding their limitations to raise new capital from the markets. As a result, from the original 45 Savings banks existing in 2008, only 12 of them remained by the end of 2012. On top of that, they have been transformed into commercial banks and their final number will be even lower, through mergers, with some additional moves still to come. What was special about the Cajas? What did it happen to them during the crisis? And why? The main goal of this Thesis is to achieve a better understanding of the particular nature of the Cajas, analyzing their behaviour and performance, and compare this with their most direct competitors (i.e., the Spanish commercial banks) using a long enough period that includes both a boom period and the years of the crisis. We believe that such approach will help us to answer the questions mentioned above, adding new elements to a debate that has been really extensive but not exhausted. Nonetheless, a debate on the Cajas fall has rarely gone beyond the political and public media spheres, where simple arguments such as the politicization have been pointed out as the unique source of the problem. The lack of academic work analyzing this relevant topic in an in-depth manner is noticeable. Thus, the purpose of this Thesis is to analyze the Cajas under several although related (and quite differentiated) angles in order to grasp the underlying nature of their large financial distress and later disappearance. We consider that this differentiated approach to a complex problem will allow us a broader and more innovative interpretation of the different events and behaviours involved

TosKÄ

2014/201

Who benefits from HEIs engagement? An analysis of priority stakeholders and activity profiles of HEIs in the United Kingdom

It has been suggested that higher education institutions (HEIs) may develop different activity profiles (including research, teaching and socio-economic engagement) in their attempt to maximise the fit between institutional resources and strategic opportunities; the latter include strategies of engagement with different groups of external stakeholders. Understanding the extent to which HEIs' resources and activity profiles are aligned with their strategic prioritisation of stakeholder groups allows us to better understand the different ways in which HEIs drive socioeconomic development. Using non-parametric techniques - qualitative and quantitative ordinal multidimensional scaling - applied to data on the universe of HEIs in the United Kingdom, we show that HEIs with different institutional resources and undertaking different sets of activities prioritise their engagement with different stakeholder groups. We also confirm the complex associations between HEIs' institutional resources, activity profiles and stakeholder prioritisation strategies, which lock HEIs into configurations that are difficult to change

TosKÄ

2014/201

Defining typologies of universities through a DEA-MDS analysis: An institutional characterization for formative evaluation purposes

Universities are organizational structures with individual activity mixes or strategies that lead to different performance levels by mission. Evaluation techniques based on performance indicators or rankings risk rewarding just a specific type of university and undermining university diversification: they usually introduce homogenizing pressures and risk displacing university objectives¿neglecting their socio-economic contribution and focusing on succeeding on the evaluation system. In this study, we propose an alternative evaluation method that overcomes these limitations. We produce a multidimensional descriptive classification of universities into typologies, while analysing the relation between their institutional factors (characteristics) and their (technical) efficiency performance from a descriptive perspective. To do so we apply bootstrap data envelopment analysis (DEA) and multidimensional scaling analysis (MDS), performing a so-called DEA-MDS analysis on data n the Spanish university system, and unlike previous studies, we include data on an important dimension of the third mission of universities (specifically knowledge transfer, KT) in their characterization. We identify six types of (homogeneous) universities. Results indicate that to be fairly efficient, universities may focus on teaching, KT, or overall efficiency but always have to fairly perform in research. Additionally, results confirm the relevance of the third mission as a source of institutional diversity in higher education. This approach could be used to address an alternative evaluation methodology for higher education institutions with formative purposes, evaluating universities according to their unique characteristics for the improvement of HE systems