<p>This paper concerns the ideas on society, policies and economic thoughts on Ireland before the cataclysmal famine of the 1840s. Senior, classified as one of the classical economists, elaborated these in the period 1829 – 1836, thus during the period of Parliamentary reform. As a trusted counsellor of the Whig governments, Senior advocated measures opposite to the common notions of laissez-faire. His basic ideas are contrasted to those of Malthus concerning economics and, in particular, the population doctrine that Senior never believed in and in its crudest form refuted. Senior regarded Malthus’ doctrine as devastating to governmental policies. Senior wanted an efficient and strong government. Moreover, Senior evolved ideas, in fact a strategy, for raising Ireland out of her common destitution instead of institutionalizing poor laws. This strategy embraced Catholic emancipation, education, public investments in infrastructure and emigration. His ideas, and proposals akin to Senior’s, are related to the political discourse of the day, which took a more common view of laissez-faire during the period considered. Nevertheless, there is consistency in his ideas on government, public investments and laissez-faire. Senior cannot be described as anything other than an early liberal and a classical economist and, hence, an advocator of economic laissez-faire. This paper underlines the need for a clear distinction between economic laissez-faire as a concept and the concept of political laissez-faire, whereas the former concerns thoughts on economics and the latter is related to the notion of the impassivity of the period of today’s discourse.</p>

This paper concerns the ideas on society, policies and economic thoughts on Ireland before the cataclysmal famine of the 1840s. Senior, classified as one of the classical economists, elaborated these in the period 1829 – 1836, thus during the period of Parliamentary reform. As a trusted counsellor of the Whig governments, Senior advocated measures opposite to the common notions of laissez-faire. His basic ideas are contrasted to those of Malthus concerning economics and, in particular, the population doctrine that Senior never believed in and in its crudest form refuted. Senior regarded Malthus’ doctrine as devastating to governmental policies. Senior wanted an efficient and strong government. Moreover, Senior evolved ideas, in fact a strategy, for raising Ireland out of her common destitution instead of institutionalizing poor laws. This strategy embraced Catholic emancipation, education, public investments in infrastructure and emigration. His ideas, and proposals akin to Senior’s, are related to the political discourse of the day, which took a more common view of laissez-faire during the period considered. Nevertheless, there is consistency in his ideas on government, public investments and laissez-faire. Senior cannot be described as anything other than an early liberal and a classical economist and, hence, an advocator of economic laissez-faire. This paper underlines the need for a clear distinction between economic laissez-faire as a concept and the concept of political laissez-faire, whereas the former concerns thoughts on economics and the latter is related to the notion of the impassivity of the period of today’s discourse.

This thesis examines the development of self-help as an ideology and as an organisational principle for poor relief and how it came to dominate discussions over poverty and crucially inform the Poor Law Amendment Act of 1834. The continuity of self-help with earlier discussions and reviews of the poor laws is explored and emphasised, as is the continuing moral core of poor relief despite historians’ frequent ascription of de-moralisation to the new political economy that came to heavily influence poor law discourse. The thesis analyses the evolution of the poor laws and of attitudes to poverty and begins with an examination of a divergence in the discourse relating to poverty between a more formal and centralised institutional approach and a more devolved, permissive institutional approach; the latter gained precedence due to its closer proximity to a dominant mode of thinking (as analysed by A. W. Coats) about the poor that held self-betterment as offering a solution to poverty most appropriate to the governance structures of the day. The greater role given to self-betterment and the natural affinity of more devolved schemes with a macroeconomic political economy framework pushed the evolution of poor law discourse along a route of emphasising individual probity and agency over the established model of community cohesion. Parallel to this divergence was the development of distinct intellectual traditions within poor law discourse between the older natural-law tradition of a natural right to subsistence and a new ideology of the natural law of markets and of competition for resources. By analysis of the thought of writers such as Thomas Robert Malthus, Jeremy Bentham, Patrick Colquhoun, David Davies, Frederick Morton Eden, Edmund Burke, etc., it is shown that this newer conception of natural law, encompassing a less interventionist and more macroeconomic approach (involving the deployment of statistics and abstraction, as explored by S. Sherman), proved more compatible with the devolved, more permissive institutional approach and so came to take precedence over that of the natural right to subsistence, which was associated more with traditional paternalism and community-level responses to scarcity and poverty. The natural law tradition spoke more to the abstract conceptions of poverty associated at this time with the greater deployment of statistics and tables in the analysis of social problems. It is demonstrated how writers of the period utilised utilitarian conceptions and nascent political economic arguments to portray the greater good of the country as a whole as possessed of greater moral and economic authority than more traditional ‘moral economy’ responses, and that vocabularies of virtue and duty were used to illustrate and justify such a shift. This set the scene for self-betterment as an economic strategy to evolve into an ideology of self-help which was developed as the panacea of poverty and the answer to the social dislocations caused by industrialisation. Self-help came to the fore as an approach that was more politically resonant in the era of revolutionary France and which enabled a more permissive institutional apparatus to be advanced. These institutions, such as allotments, savings banks and schools of industry, came to prominence in the period 1816-1820 and pertained more to macroeconomic understandings of poverty. They were expounded using a theme, that of ‘character’, that described poverty as the result of personal imprudence and hence as treatable, the most appropriate level for this treatment being that of the individual. The reforms of 1818-19 and the debates that informed them are given an extended analysis as they formed the crucial juncture in the cohering of self-help as an ideology and a paradigmatic shift in poor law policy towards greater discrimination underwritten by self-help. Finally, the 1834 Poor law Reform Act is explained in terms of the ideological development of arguments of self-help and character towards a more punitive and disciplinarian platform for enforcing self-help, with the cost-efficient and systematic institutional approach of Bentham adapted to the purpose.

Division One: “Malthus Gets Fat” (Two Chapters) Chapter One develops a simple dynamic model to examine the takeoff from a Malthusian economy to a modern growth regime. It finds that several factors, most notably the rate of technological progress and the economic structure, determine the fastest rate at which the population can grow without declining living standards; this is termed maximum sustainable population growth. It is only when this maximum sustainable rate exceeds the peak rate at which a society expands that takeoff can occur. I also investigate the effects of trade and international income transfers on the ability to sustain takeoff. It is also shown that present income growth is not necessarily indicative of the ability to sustain takeoff and that factors which increase current income growth may actually inhibit takeoff, and vice versa. Chapter Two applies the sustainable population growth framework to Britain during the Industrial Revolution. The model shows a dramatic increase in sustainable population growth at the time of the Industrial Revolution, well before the beginning of modern levels of income growth. The main contributions to the British breakout were technological improvements and structural change away from agricultural production. At least until the middle of the 19th Century, coal, capital and trade played a minor role. Division Two: “Leverage and Financial Market Instability” (Four Chapters) Chapter One develops a model of how leverage induces explosive behavior in financial markets. I show that when levered investors become too large relative to the market as a whole, the demand curve for securities can suddenly become upward-sloping as levered investors are exposed to forced liquidations. The size and leverage of all levered investors defines the minimum elasticity-adjusted market size for stability or MinEAMASS, which is the smallest elasticity-adjusted market size that can support the group of levered investors analyzed. This gives rise to a measure of instability that can predict when markets become vulnerable to a leverage-driven market liquidity crisis. Chapter Two iterates the model of Chapter One forward in time to generate an inflating bubble that suddenly bursts, reproducing many of Kindleberger's (1996) stylized facts about the dynamics of bubbles in a simple framework. Chapter Three applies my measure of instability in a historical investigation of the 1998 demise of hedge fund Long-Term Capital Management (LTCM). I find that a forced liquidation of LTCM threatened to destabilize some financial markets, particularly for bank funding and equity volatility. Chapter Four discusses how the model applied to the stock market crash of 1929. There the evidence suggests that a tightening of margin requirements in the first nine months of 1929 combined with price declines in September and early October caused enough investors to become constrained that the market was tipped into instability, triggering the sudden crash of October and November.

L'accroissement de plus en plus rapide de la population mondiale pousse un grand nombre de chercheurs à s'interroger sur les limites de la croissance. Dans le même ordre d'idée, cette recherche vise à comprendre la dynamique entourant l'économie et la démographie. Une analyse exhaustive des différents écrits d'économistes permet d'approfondir la connaissance sur ce sujet précis de même qu'à répondre à une question en particulier: Quelles politiques doivent être mises en place pour améliorer le sort des affamés? Thomas Robert Malthus est l'un des premiers à avoir remis en question l'efficacité d'un accroissement de la population. Sa critique de certains des thèmes clés du courant mercantilisme marque ainsi le commencement d'une analyse privilégiant le bonheur individuel sur celui de la nation. Après s'être penché sur les différentes propositions développées par Malthus dans ses Essais sur le principe de population, il s'avère possible d'examiner l'influence qu'il a eue sur deux autres économistes, soit John Maynard Keynes et Karl Gunnar Myrdal. La présente étude analyse ainsi les idées de Keynes et de Myrdal quant à la relation économie-démographie. Bien que Keynes et Myrdal aient modifié au fil du temps leur vision quant à un accroissement démographique, il n'en demeure pas moins qu'ils conservèrent un argumentaire basé sur les théories malthusiennes. Après avoir examiné les différentes politiques démographiques proposées par ces économistes, une dernière section permet de prendre conscience des développements récents dans l'économie de la population. De plus, les politiques proposées par Malthus, Myrdal et Keynes sont analysées dans une perspective contemporaine où l'Inde et la Chine occupent une place prépondérante. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : John Maynard Keynes, Thomas Robert Malthus, néo-malthusianisme, Karl Gunnar Myrdal, population, redistribution des revenus

本文認為，1950年代馬寅初被批判一事，不論就其性質或時期，都與反右運動不同，只是有時間上一部分的重疊，有必要重新釐清。馬寅初有關計劃生育的主張，並非首倡，中共黨內的毛澤東，中共黨外的邵力子等人，比起馬寅初，在中共建政後對人口問題的重視，在時間點上都比馬寅初要早。毛澤東自始至終，始終強調要有計劃地控制人口。馬寅初所關切的，表面上是人口問題，實際上是中國大陸當時經濟積累的效率，因為這將影響中國大陸工業化的速度。若拉長時間縱深來看，馬寅初事件背後所呈現出來的，是馬爾薩斯主義和馬克思主義對於中國大陸人口研究典範的領導權爭奪戰，歷經四十年，馬克思主義終於取得優勢。而馬寅初作為一位知識份子，與其他同類型的傾左知識份子，在中共建政之後，政治上日漸認同中共，在思想上自覺地馬克思主義化，但多數不為那些更早轉向馬克思主義、掌握了馬克思主義在中國的詮釋權的人所接納，最終，大多在文革以前，便已受到不同程度的排擠和批判。 / This essay will argue that the Ma Yin-Chu incident and the Anti-Rightist Campaign is not the same thing, neither on the period nor on the nature, and he is not the first one who advocated birth control when he announced his article “New Principle of Population” in 1957. Instead, Mao Tze-Dong and the CCP have been promoted birth control several years ago. Besides, the aim of “New Principle of Population” focused on the economical accumulation for industrialization, not for birth control itself. On the other hand, if we consider this incident historically, we can see there are two diachronic trends: One is the struggle of the hegemony of China’s population research between the Malthusism and Marxism, this struggle lasts over 40years since the May-forth Movement, and in1960s’, the winner is Marxism. The other is there were many left-leaning intellectuals who changed their political or philosophical position into the CCP or Marxism since 1940s’, like Ma Yin-Cu, didn’t be affiliated by those intellectuals who had change their position before the “Yan-An Rectification” in 1942. Most of them like Ma Yin-Cu have been criticized before the Cultural Revolution.

I detta tvärvetenskapliga arbete studeras från den matematiska sidan tre klassiska populationsmodeller: Malthus tillväxtmodell, Verhulsts logistiska modell och Lotka-Volterras jägarebytesmodell. De klassiska modellerna jämförs med stokastiska. De stokastiska modeller som studeras är födelsedödsprocesser och deras diffusionsapproximation. Jämförelse görs med medelvärdesbildade simuleringar. Det krävs många simuleringar för att kunna genomföra jämförelserna. Dessa simuleringar måste utföras i datormiljö och det är här den datalogiska aspekten av arbetet kommer in. Modellerna och deras resultathantering har implementerats i både MatLab och i C, för att kunna möjliggöra en undersökning om skillnaderna i tidsåtgången mellan de båda språken, under genomförandet av ovan nämnda jämförelser. Försök till tidsoptimering utförs och även användarvänligheten under implementeringen av de matematiska problemen i de båda språken behandlas. Följande matematiska slutsatser har dragits, att de medelvärdesbildade lösningarna inte alltid sammanfaller med de klassiska modellerna när de simuleras på stora tidsintervall. I den logistiska modellen samt i Lotka-Volterras modell dör förr eller senare de stokastiska simuleringarna ut när tiden går mot oändligheten, medan deras deterministiska representation lever vidare. I den exponentiella modellen sammanfaller medelvärdet av de stokastiska simuleringarna med den deterministiska lösningen, dock blir spridningen stor för de stokastiska simuleringarna när de utförs på stora tidsintervall. Datalogiska slutsatser som har dragits är att när det kommer till att implementera få modeller, samt resultatbearbetning av dessa, som ska användas upprepade gånger, är C det bäst lämpade språket då det visat sig vara betydligt snabbare under exekvering än vad MatLab är. Dock måste hänsyn tas till alla de svårigheter som implementeringen i C drar med sig. Dessa svårigheter kan till stor del undvikas om implementeringen istället sker i MatLab, då det därmed finns tillgång till en uppsjö av väl lämpade funktioner och färdiga matematiska lösningar. / In this interdisciplinary study, three classic population models will be studied from a mathematical view: Malthus’ growth, Verhulst’s logistic model and Lotka-Volterra’s model for hunter and prey. The classic models are being compared to the stochastic ones. The stochastic models studied are the birthdeath processes and their diffusion approximation. Comparisons are made by averaging simulations. It requires numerous simulations to carry out the comparisons. The simulations must be carried out on a computer and this is where the computer science emerges to the project. The models, along with the handling of the results, have been implemented in both MatLab and in C in order to allow a comparison between the two languages whilst executing the above mentioned study. Attempts to time optimization and an evaluation concerning the user-friendliness regarding the implementation of mathematical problems will be performed. Mathematic conclusions, which have been drawn, are that the averaging solutions do not always coincide with the traditional models when they are being simulated over large time. In the logistic model and in Lotka-Volterra’s model the stochastic simulations will sooner or later die when the time is moving towards infinity, whilst their deterministic representation keeps on living. In the exponential model, the mean values of the stochastic simulations and of the deterministic solution coincide. There is, however, a large spread for the stochastic simulations when they are carried out over a large time. Computer scientific conclusions drawn from the study includes that when it comes to implementing a few models, along with the handling of the results, to be used repeatedly, C is the most appropriate language as it proved to be significantly faster during execution. However, all of the difficulties during the implementation of mathematical problems in C must be kept in mind. These difficulties can be avoided if the implementation instead takes place in MatLab, where a numerous of mathematical functions and solutions will be available.

<p>I detta tvärvetenskapliga arbete studeras från den matematiska sidan tre klassiska populationsmodeller: Malthus tillväxtmodell, Verhulsts logistiska modell och Lotka-Volterras jägarebytesmodell. De klassiska modellerna jämförs med stokastiska. De stokastiska modeller som studeras är födelsedödsprocesser och deras diffusionsapproximation. Jämförelse görs med medelvärdesbildade simuleringar.</p><p>Det krävs många simuleringar för att kunna genomföra jämförelserna. Dessa simuleringar måste utföras i datormiljö och det är här den datalogiska aspekten av arbetet kommer in. Modellerna och deras resultathantering har implementerats i både MatLab och i C, för att kunna möjliggöra en undersökning om skillnaderna i tidsåtgången mellan de båda språken, under genomförandet av ovan nämnda jämförelser. Försök till tidsoptimering utförs och även användarvänligheten under implementeringen av de matematiska problemen i de båda språken behandlas.</p><p>Följande matematiska slutsatser har dragits, att de medelvärdesbildade lösningarna inte alltid sammanfaller med de klassiska modellerna när de simuleras på stora tidsintervall. I den logistiska modellen samt i Lotka-Volterras modell dör förr eller senare de stokastiska simuleringarna ut när tiden går mot oändligheten, medan deras deterministiska representation lever vidare. I den exponentiella modellen sammanfaller medelvärdet av de stokastiska simuleringarna med den deterministiska lösningen, dock blir spridningen stor för de stokastiska simuleringarna när de utförs på stora tidsintervall.</p><p>Datalogiska slutsatser som har dragits är att när det kommer till att implementera få modeller, samt resultatbearbetning av dessa, som ska användas upprepade gånger, är C det bäst lämpade språket då det visat sig vara betydligt snabbare under exekvering än vad MatLab är. Dock måste hänsyn tas till alla de svårigheter som implementeringen i C drar med sig. Dessa svårigheter kan till stor del undvikas om implementeringen istället sker i MatLab, då det därmed finns tillgång till en uppsjö av väl lämpade funktioner och färdiga matematiska lösningar.</p> / <p>In this interdisciplinary study, three classic population models will be studied from a mathematical view: Malthus’ growth, Verhulst’s logistic model and Lotka-Volterra’s model for hunter and prey. The classic models are being compared to the stochastic ones. The stochastic models studied are the birthdeath processes and their diffusion approximation. Comparisons are made by averaging simulations.</p><p>It requires numerous simulations to carry out the comparisons. The simulations must be carried out on a computer and this is where the computer science emerges to the project. The models, along with the handling of the results, have been implemented in both Mat- Lab and in C in order to allow a comparison between the two languages whilst executing the above mentioned study. Attempts to time optimization and an evaluation concerning the user-friendliness regarding the implementation of mathematical problems will be performed.</p><p>Mathematic conclusions, which have been drawn, are that the averaging solutions do not always coincide with the traditional models when they are being simulated over large time. In the logistic model and in Lotka-Volterra’s model the stochastic simulations will sooner or later die when the time is moving towards infinity, whilst their deterministic representation keeps on living. In the exponential model, the mean values of the stochastic simulations and of the deterministic solution coincide. There is, however, a large spread for the stochastic simulations when they are carried out over a large time.</p><p>Computer scientific conclusions drawn from the study includes that when it comes to implementing a few models, along with the handling of the results, to be used repeatedly, C is the most appropriate language as it proved to be significantly faster during execution. However, all of the difficulties during the implementation of mathematical problems in C must be kept in mind. These difficulties can be avoided if the implementation instead takes place in MatLab, where a numerous of mathematical functions and solutions will be available.</p>

<p>I detta tvärvetenskapliga arbete studeras från den matematiska sidan tre klassiska populationsmodeller: Malthus tillväxtmodell, Verhulsts logistiska modell och Lotka-Volterras jägarebytesmodell. De klassiska modellerna jämförs med stokastiska. De stokastiska modeller som studeras är födelsedödsprocesser och deras diffusionsapproximation. Jämförelse görs med medelvärdesbildade simuleringar.</p><p>Det krävs många simuleringar för att kunna genomföra jämförelserna. Dessa simuleringar måste utföras i datormiljö och det är här den datalogiska aspekten av arbetet kommer in. Modellerna och deras resultathantering har implementerats i både MatLab och i C, för att kunna möjliggöra en undersökning om skillnaderna i tidsåtgången mellan de båda språken, under genomförandet av ovan nämnda jämförelser. Försök till tidsoptimering utförs och även användarvänligheten under implementeringen av de matematiska problemen i de båda språken behandlas.</p><p>Följande matematiska slutsatser har dragits, att de medelvärdesbildade lösningarna inte alltid sammanfaller med de klassiska modellerna när de simuleras på stora tidsintervall. I den logistiska modellen samt i Lotka-Volterras modell dör förr eller senare de stokastiska simuleringarna ut när tiden går mot oändligheten, medan deras deterministiska representation lever vidare. I den exponentiella modellen sammanfaller medelvärdet av de stokastiska simuleringarna med den deterministiska lösningen, dock blir spridningen stor för de stokastiska simuleringarna när de utförs på stora tidsintervall.</p><p>Datalogiska slutsatser som har dragits är att när det kommer till att implementera få modeller, samt resultatbearbetning av dessa, som ska användas upprepade gånger, är C det bäst lämpade språket då det visat sig vara betydligt snabbare under exekvering än vad MatLab är. Dock måste hänsyn tas till alla de svårigheter som implementeringen i C drar med sig. Dessa svårigheter kan till stor del undvikas om implementeringen istället sker i MatLab, då det därmed finns tillgång till en uppsjö av väl lämpade funktioner och färdiga matematiska lösningar.</p> / <p>In this interdisciplinary study, three classic population models will be studied from a mathematical view: Malthus’ growth, Verhulst’s logistic model and Lotka-Volterra’s model for hunter and prey. The classic models are being compared to the stochastic ones. The stochastic models studied are the birthdeath processes and their diffusion approximation. Comparisons are made by averaging simulations.</p><p>It requires numerous simulations to carry out the comparisons. The simulations must be carried out on a computer and this is where the computer science emerges to the project. The models, along with the handling of the results, have been implemented in both MatLab and in C in order to allow a comparison between the two languages whilst executing the above mentioned study. Attempts to time optimization and an evaluation concerning the user-friendliness regarding the implementation of mathematical problems will be performed.</p><p>Mathematic conclusions, which have been drawn, are that the averaging solutions do not always coincide with the traditional models when they are being simulated over large time. In the logistic model and in Lotka-Volterra’s model the stochastic simulations will sooner or later die when the time is moving towards infinity, whilst their deterministic representation keeps on living. In the exponential model, the mean values of the stochastic simulations and of the deterministic solution coincide. There is, however, a large spread for the stochastic simulations when they are carried out over a large time.</p><p>Computer scientific conclusions drawn from the study includes that when it comes to implementing a few models, along with the handling of the results, to be used repeatedly, C is the most appropriate language as it proved to be significantly faster during execution. However, all of the difficulties during the implementation of mathematical problems in C must be kept in mind. These difficulties can be avoided if the implementation instead takes place in MatLab, where a numerous of mathematical functions and solutions will be available.</p>

Esta tesis doctoral es una colección de tres artículos. Los capítulos 1 y 2, co-autorados con Joachim Voth, investigan por qué Europa en 1700 ya era más rico que el resto del mundo y por qué Inglaterra fue el primer país en industrializarse. Encontramos que las dinámicas de la población, en lugar del crecimiento de la productividad, fueron los promotores más importantes del desarrollo económico de Europa Occidental durante la temprana edad moderna (1450-1700). Calibramos un modelo probabilístico para representar Inglaterra en 1700 y encontramos que ingresos iniciales más altos unidos a limitaciones de fertilidad aumentaron la probabilidad de industrialización. En el tercer capítulo, presento un nuevo hecho estilizado y analizo su contribución al sesgo del cambio tecnológico hacia los trabajadores más cualificados: El porcentaje de trabajadores cualificados en la producción intermedia está altamente correlacionado con la proporción de trabajo cualificado en la producción final. Esto genera un efecto multiplicador que refuerza la demanda de trabajo cualificado a lo largo de la cadena de producción. El efecto es importante, explica más de un tercio del aumento de la demanda de trabajadores cualificados en la industria manufacturera de EE.UU. / This dissertation is a collection of three essays. Chapters 1 and 2, co-authored with Joachim Voth, investigate the question why Europe in 1700 was ahead of the rest of the world and why England was the first country to industrialize. We find that population dynamics, rather than productivity growth, were the most important drivers for Western Europe to overtake China in the early modern period (1450-1700). We calibrate a probabilistic model to match England in 1700 and find that higher initial per capita incomes together with fertility limitation increased its industrialization probabilities. In the third chapter, I present a novel stylized fact and analyze its contribution to the skill bias of technical change: The share of skilled labor embedded in intermediate inputs correlates strongly with the skill share employed in final production. This delivers a multiplier that reinforces skill demand along the production chain. The effect is large, accounting for more than one third of the observed skill upgrading in U.S. manufacturing.