Cette thèse explore des aspects du monde naturel par la lentille de l'information algorithmique. La notion de l'émergence, intuitivement reliée à tant de phénomènes naturels, se voit offrir une définition cadrée dans le domaine plus spécifique des statistiques algorithmiques. Capturant toutes deux l'organisation non triviale d'un objet, la sophistication et la profondeur logique sont relativisées à un objet auxiliaire puis remises en relation. Enfin, des modèles proposant une description locale des systèmes quantiques sont démontrés équivalents, ont leur coût de description quantifié et sont généralisés aux systèmes continus. / This thesis explores aspects of the physical world through the lens of algorithmic information. The notion of emergence, intuitively linked to many natural phenomena, is offered a definition framed in the field of algorithmic statistics. Both capturing non-trivial organization of an object, sophistication and logical depth are compared once relativized to an auxiliary object. Finally, models proposing a local description of the quantum systems are shown equivalent, have their description cost quantified and are generalized to continuous systems.

and Key Words The linguistic concept of complexity as a component of the CAF triad is used to describe the complexity of texts, either spoken (transcribed) or written, and to describe speaker advancedness not only in L1, but also in L2 research. On the most basic level, lexical complexity and syntactic complexity can be distinguished, however, complexity is a multidimensional concept and many different descriptions and operationalisations exist; there is an even wider gap in terms of measuring lexical complexity of L2 oral speech with lexical frequency wordlists as studies on lexical sophistication have yielded inconsistent and sometimes inconclusive results; the majority of studies on lexical sophistication, one of the subdivisions of lexical complexity, have been carried out on written learner production. For this reason, this thesis focuses on measuring lexical complexity in L2 speech with word frequency lists; more specifically, it presumes that C1 speakers would produce more of complex vocabulary (low-frequency vocabulary) than B2 speakers in our sample; this thesis also attempts to correlate word frequency list results with English Vocabulary Profile results and compare the individual speakers. For this analysis 10 B2 and 10 C1 Czech speakers of English were selected from the LINDSEI spoken...

<p>This dissertation consists of three major chapters. The first chapter is dedicated to testing a novel gravity model of international trade, while the last two chapters explore cross-country commitment and implementation behavior within the World Trade Organization’s Trade Facilitation Agreement. </p> <p><strong>Chapter 1:</strong> I test a novel theoretical gravity model of international trade on firm-level export data from Colombia in 2018. The model assumes a power law relationship between trade flows and distance, with the distance elasticity resulting from two dynamic processes: firm-export growth captured in a Pareto distribution; and the growth of the distance over which those exports are sold. Although the model has been shown to work well in French data, its usefulness for interpreting data from other countries remains unexplored. I find evidence that the model fails in Colombia because some large firms contradict its assumptions by exhibiting shorter export distances compared to smaller firms in the sample. I hypothesize that these large firms are branches of foreign multinational corporations (MNCs). MNCs’ headquarters constraint the export growth of its affiliates as well as the markets they reach. While I cannot prove firms’ MNC affiliation, I use export sophistication as an imperfect metric to reflect MNC presence. When MNC affiliates are excluded from the sample, firm export distance rises faster with firm size, leading to improved predictions of the distance elasticity of trade in Colombia by the model. These findings have implications not only for the tested model but also for other theories that explain gravity in international trade through firm-level behavior.</p> <p><strong>Chapter 2:</strong> We use a new database of commitments made during the process of ratifying the Trade Facilitation Agreement (TFA) to study variation in countries’ commitment behavior. The TFA is a novel World Trade Organization agreement because it allows developing countries to select commitments from a menu of best practices in trade facilitation, rather than to consent, or not, to a comprehensive package of negotiated commitments. The operation of this <em>à la carte</em> approach to concluding trade agreements is worthy of study in its own right, but the commitment data also offer a high-level description of progress in an international effort to improve border management procedures around the globe. Our study uses data on TFA commitments to describe progress across subcomponents of the agreement. A regression model shows that the number of Type A trade facilitation commitments that a country made in the TFA ratification process depends on its level of development, population size, ability to control corruption, and foreign aid received to support trade facilitation. We use multidimensional scaling techniques to study differences in the content of national commitment bundles. This approach demonstrates that variation in the content of countries’ commitments is closely tied to the number of commitments made.</p> <p><strong>Chapter 3:</strong> This chapter examines the implementation progress of the Trade Facilitation Agreement (TFA) from 2019 to 2023. The TFA, which is the latest World Trade Organization agreement, came into force in 2017. In its novelty, it allows developing countries to set their own implementation schedule and adjust it if needed. This flexibility aligns implementation requirements with the capabilities of signatory countries, but introduces uncertainties in achieving complete global implementation and fully realizing the potential benefits of the agreement. Using data on the notified implementation dates for each measure of the TFA, this study describes the progress made in implementing different subcomponents of the agreement over a period of five years. A regression analysis suggests that the annual rate of progress towards achieving full TFA implementation does not vary based on country characteristics such as GDP per capita, population size, or landlocked status. Assuming that the tendency at which countries implement measures remains unchanged, I project that 95% of developing countries will achieve 95% TFA implementation between the years 2036 and 2047.</p>