扬·廷贝亨Jan Tinbergen

扬·廷贝亨的父亲德克Cornelis Tinbergen（1874-1951）是海牙文理中学的一名教授荷兰语的教师，但也是一位中世纪荷兰语学者。Dirk Tinbergen于1902年在斯海弗宁恩与珍妮特·范·埃克（1877-1960）结婚，她在结婚前是一名小学教师。珍妮特的父亲尼古拉斯·范·埃克是一名数学教师。婚后，珍妮特做一些私人辅导，为家庭赚些额外的钱。本传记的主人公廷贝亨是他父母五个孩子中的老大，四个男孩和一个女孩。他的一个弟弟尼古拉斯廷贝亨（1907-1988）成为著名的生理学家，并于1973年获得诺贝尔生理学奖。他最年轻的弟弟卢克廷贝亨（1916-1955）成为著名的鸟类学家。廷贝亨的另外两个兄弟姐妹是雅科米娜（生于1905年）和迪克（生于1909年）。然而，廷贝亨家里不止这五个孩子，因为他们还照顾那些在荷属东印度群岛长期逗留的父母的孩子，并且在第一次世界大战期间，他们收留了一些比利时和奥地利难民。Dirk Tinbergen的[17]：-

……对语言和艺术的热爱传给了他的孩子们；他偶尔的户外绘画课以及在暑假期间与孩子们散步和骑自行车，促成了这个家庭愉快而充满智识的氛围，这种氛围是教育的特征。母亲珍妮特·范·埃克，无论从她管理廷贝亨家庭的谦逊方式，还是从她对数学的兴趣来看，都体现了家庭的秩序和规律。

廷贝亨上了小学，获得了一份证书，上面写着他是“一名最优秀的学生”。然后他上了海牙的Hogere Bugerschool，在那里他最喜欢的科目是科学和数学。这是一种特殊类型的学校，专为中产阶级父母希望提升自己地位的孩子设计。这些学校允许在通过拉丁语和希腊语的额外考试后进入大学系统，而廷贝亨做到了这一点。在这所学校期间，廷贝亨的社会和政治观点形成了，部分是由于第一次世界大战的恐怖，他通过难民的眼睛看到了这些，部分是由于他与蒂内·约翰娜·德·维特（1902-1991）的友谊，后者后来成为他的妻子。他于1921年进入莱顿大学。在[30]中，他解释了自己在大学选择课题的原因：-

我想快点完成学业，然后转向经济学。现在你可以问我为什么选择了物理学，但这显然是我真正的兴趣。我非常喜欢物理学和数学，我也觉得那可能是我最擅长的东西，但与此同时，我已经确信，作为一名经济学家，我可能对社会更有用。我认为大多数更大的政治讨论是经济性的而非物理性的，所以我希望获得足够的能力用数学来处理事情，也许把物理学作为比经济学更发达的科学的一个例子。

他在莱顿大学学习数学和理论物理学，在那里受保罗·埃伦费斯特的影响最大。1987年在报纸NRC-Handelsblad上撰文时，他这样评价他在莱顿的老师们[29]：-

我受保罗·埃伦费斯特影响很大。我在一个许多有趣的人聚在一起的时代学习物理。保罗·埃伦费斯特不会那样讲课，因为他更喜欢对话。多亏了他，我才能参与与阿尔伯特·爱因斯坦的讨论。卡末林·昂内斯、亨德里克·洛伦兹和埃里克·克里斯托弗·齐曼也在场。作为学生，能在这样的老师手下学习，你确实非常幸运。

廷贝亨也有与他的左翼观点相关的政治兴趣。在大学里，他创立了一个社会民主学生俱乐部，还创办了一份学生报纸。事实上，廷贝亨最早的一些出版物就是他为社会主义报纸Het Volk撰写的文章，他在其中考察了1920-22年经济萧条对失业的影响以及穷人的生活如何受到影响。在本科期间，他成为了工党[24]的成员：-

1923年，我成为了工党及其青年组织的成员；我接触到了莱顿的贫困阶层，这通常是学生不太了解的。回想起来，我不知道自己是否足够聪明能为现代物理学做出贡献；无论如何，我的兴趣在于帮助改变社会。

在莱顿完成本科学位后，廷贝亨继续在莱顿攻读博士学位，由保罗·埃伦费斯特指导。然而，他不得不服兵役，但他的政治观点意味着他不愿意这样做。他很幸运，因为就在几年前，1923年，荷兰通过了立法，允许出于良心拒服兵役者避免兵役。该立法要求出于良心拒服兵役者改为从事政府服务。廷贝亨被分配到鹿特丹州立监狱的一个行政职位，他将在那里服务十五个月。然而，他的父亲试图为儿子争取一个更好、更令人满意的职位，由于他的干预，廷贝亨获准转到海牙的荷兰政府中央统计局。他已经服完了十五个月中的五个月，所以只需在中央统计局再服务十个月。当他在1928年完成这十个月时，局长说服他在那里担任永久职位。他同意了，条件是允许他休假一段时间来完成他的博士论文。

廷贝亨于1929年提交了他的学位论文Minimumproblemen in de natuurkunde en de ekonomieⓉ（物理学和经济学中的极小值问题）。它结合了数学、物理学和经济学。在引言中，廷贝亨感谢保罗·埃伦费斯特向他指出了一个可以让他将数学理论与他的政治兴趣结合起来的课题。论文的主要部分是数学的，研究极小化问题。然后他给出了两个附录，一个描述数学在物理学中的应用，第二个附录给出在经济学中的应用。廷贝亨这项工作的意义在于，它是数学中一个新思想的最早例子之一，即数学建模。当然，数学物理在整个数学史中一直有人研究，但廷贝亨的工作为数学的应用开辟了一条新路径，其应用可以涉及广泛的领域。

从1929年到1945年，他在统计局担任统计员，但在1930年代初的几年里，他还在阿姆斯特丹大学任教。在统计局，他解释道[30]：-

我负责期刊《De Nederlandsche Conjunctuur》。它始于1929年，但战争使它终止。我作为编辑的官方职责给了我相当大的自由。监督我工作的人负责建立类似伦敦和剑桥经济服务处的东西，关注荷兰经济的周期性前景。

他对中央统计局的影响在17中有描述：-

三十年代在海牙中央统计局的生活一点也不枯燥。大萧条造成的失业问题迫使人们要求为政策目的提供统计数据。尽管中央统计局已经从事商业周期统计工作有一段时间了，但直到成立商业周期研究部门才获得重大推动。廷贝亨刚刚完成学位论文并进入统计人员队伍，就被任命负责这个新部门。显然受到柏林和法兰克福的德国商业周期研究所的影响，廷贝亨逐渐尝试发展一种对经济学中动态问题的经验方法。与此同时，他身边聚集了年轻的工程师、数学家和物理学家，如Johannes Bernardus Dirk Derksen、Pieter De Wolff和A Bijl。他们一起组成了所谓的“Q.C.”或“Quantitatieven Club”，这是一个由既关心社会又具有定量或数学取向的年轻人组成的非正式团体。他们与其他人，如特亚林·科普曼斯，一起参与小型讨论小组，评估当代经济学的贫乏以及需要更严谨方法的必要性。

1930年，他是计量经济学会的创始人之一33：-

“Econometrica”，这个新学会的期刊，为展示和讨论这门年轻科学的成果提供了一个急需的论坛。在这里以及计量经济学会的频繁会议中，……廷贝亨通过[他的]自身贡献以及[他的]对新一代计量经济学家的鼓舞人心的个人影响，产生了强烈的影响。

他在博士期间的经济学研究完全是理论性的，但现在他能够获取大量数据来检验和发展理论。

从1933年到1973年，他是鹿特丹荷兰经济学院的经济学教授。他被任命为荷兰工党科学局的董事会成员，并于1935年与人合著了《劳动计划》。该计划基于廷贝亨的以数学为基础的经济学原理。Gerard Alberts在8中写道：-

这些经济理性原则可能真的能起作用的假设，在一年后关于积极经济政策可能性的学术辩论中得到了廷贝亨的证实。在辩论中，廷贝亨提出了“荷兰经济的定量程式化”，通过一组定义和方程来分离重要因素及其效应。他称之为荷兰经济的“模型”（最初写作时带有引号），这个模型允许人们将一些数据投入“数学机器”，然后预测结果。

20世纪30年代末，廷贝亨在国际联盟担任科学顾问。他们邀请他统计调查Gottfried Haberler在其著作Prosperity and Depression（1937）中提出的哪些商业周期在实践中表现最好。Haberler的这本书是应国际联盟的要求写的。廷贝亨从中央统计局获得两年休假来从事这项工作。另一本启发他的书是约翰·梅纳德·凯恩斯的General Theory （1936）。Lawrence Klein写道[18]：-

在私人谈话中，廷贝亨告诉我他多么钦佩约翰·梅纳德·凯恩斯在1936年《通论》中的工作，并且他深受启发，试图提供一些经验实质并使用估计模型来实施适当的政策。遗憾的是，廷贝亨的工作受到了约翰·梅纳德·凯恩斯（1939年）如此不公正的批评对待，但作为他那样善良的人，他对约翰·梅纳德·凯恩斯没有表示任何恶意。

廷贝亨对约翰·梅纳德·凯恩斯的回应是在他的论文On a Method of Statistical Research. A Reply（1940）中，关于这场争论的细节见Kurt Dopfer的论文[13]。

1945年，他被任命为荷兰中央计划局局长。廷贝亨后来开发了其他计量经济学模型，特别是他构建了一个美国的计量经济学模型。1969年，他因这第一个宏观经济模型共同获得了首届诺贝尔经济学奖。也许我们应该引用Tinberg关于模型的原话[28]：-

在试图评估模型构建对经济科学的理论和实践做出了什么贡献时，我觉得至少我们可以说模型具有“教学”价值。在我们的教科书中，我们经常呈现简化的、甚至可以说是过度简化的现实图景，尽管如此，这些图景有助于人们理解现实的一些基本特征。……我所说的“教学价值”也代表“沟通”价值。规划专家与政治家和公民沟通的能力构成了任何类型的民主或半民主规划中的重要元素，这种沟通可以通过相对简单的模型来增强。然而，为了不歪曲现实，将需要一系列模型，如在“阶段”规划中所使用的，或者如我们现在所说的，多级规划。然而，我确实认为模型的效用超出了它们的教学价值。它们是准备良好协调政策的真实且 essential 元素。但它们不能独自完成这项工作。模型构成了一个“框架”或“骨架”，血肉必须由大量的常识和细节知识来添加。

他的主要著作包括Grondproblemen der Theoretische StatistiekⓉ（《理论统计学的基本问题》）（1936）、Statistical Testing of Business Cycles（1939）、Econometrics（1941）、On the Theory of Economic Policy（1952）、Economic Policy: Principles and Design（1956）和Income Distribution: Analysis and Policies（1975）。关于1956年的著作，Charles Lindblom写道[20]：-

[它]同时是对构建政策分析模型时遇到的一些数学问题的研究；是对数学模型及其他系统性的、但非数学的方法应用于各种示例性政策问题的展示；以及对政策制定过程是什么和应当是什么的阐述。就第一点而言，它非常出色；就第二点而言，有帮助但令人困惑；就第三点而言，我认为是错误的。

Gerard Alberts在[8]中强调了廷贝亨不仅对经济学、而且对数学的影响：-

廷贝亨在其职业生涯早期就在政治和科学两方面都取得了成功，他利用了一个几乎是自然的机会将两者结合起来。他的职业生涯基于一种选择而非两难困境，他的工作对经济学和数学都产生了重大影响。随着计量经济学的发展，它有助于推动一种使数学变得有用的新范式，即数学建模。

他对经济学的贡献由Bent Hansen总结如下[14]：-

……他不下六次将经济学向前推进了一大步。因此，（i）他是现代经济动态学的先驱；（ii）他帮助建立了计量经济学；（iii）他是经验宏观经济学创始人；（iv）他为创建现代经济预测和预报技术做出了决定性贡献；（v）他是现代经济政策理论的创始人；（vi）他对落后国家的现代发展规划做出了重大贡献。

让我们引用廷贝亨本人关于他个人“价值体系”的话[24]：-

我倾向于表明，同情弱者或受苦者是我的伦理信念的基本要素之一，宽容是另一个基本要素。虽然我是一个极力强调宽容的教会的成员，但我不确定自己是否信教；但我确信我是基督教的产物，以我自己的方式诠释。我的民主社会主义政治选择、我的欧洲联邦主义理想，以及我对第三世界的优先关注，都源于这一灵感。从消极方面看，我认为这个世界上的某些大恶似乎是民族主义和战争。

至于爱好，廷贝亨写道，他的主要爱好[24]：-

……是我对语言的兴趣：这一点我与妻子共有，并从父母那里继承。在智识上，语言学中的比较部分是最有趣的部分：比较同一个词在英语和法语中，或在德语或荷兰语中，例如“grand”，所具有的不同含义；比较意大利语和西班牙语，或瑞典语和丹麦语。……反爱好？是的，我不喜欢任何形式的运动，也不喜欢汽车。我不得不承认，有时我会感激搭个便车：这不是一贯的态度！

我们最后引用Willy Sellekaerts的话[23]：-

在海牙中产阶级街区The Haviklaan，一栋整洁、简朴、与他所在街区其他房屋几乎无法区分的房子里，住着世界上最杰出的经济学家之一，1969年首届诺贝尔经济学奖的共同获得者，一个以温和、谦逊和无私献身于人类福祉事业而闻名的人。那个人就是廷贝亨。……廷贝亨是一个谦逊的人，不向世界吹嘘自己的成就。他几乎从不批评同事。他本可以凭借自己的才能获得可观的个人收入，但他却选择献身于为他人服务。他不开车，而是乘公共汽车或有轨电车上班。众所周知，他会感谢本科生选修他的课程。他学习了许多语言，主要是为了与他在世界许多地方共事过的人更好地交流。……他喜欢画画。他相信人的尊严。他以此信念为生。

Jan Tinbergen's father, Dirk Cornelis Tinbergen (1874-1951), was a schoolmaster teaching Dutch language in the Gymnasium of The Hague but was also a scholar of Medieval Dutch. Dirk Tinbergen married Jeannette van Eek (1877-1960), who was a primary school teacher before the marriage, in Scheveningen in 1902. Jeannette's father, Nikolaas van Eek, was a mathematics teacher. After her marriage, Jeanette did some private tutoring to earn some extra money for the family. Jan, the subject of this biography, was the eldest of his parents' five children, four boys and one girl. One of his younger brothers, Nikolaas Tinbergen (1907-1988), became a famous physiologist and won the Nobel Prize for physiology in 1973. His youngest brother, Luuk Tinbergen (1916-1955), became a famous ornithologist. Jan's other two siblings were Jacomiena (born 1905) and Dik (born 1909). However, there were more than these five children in the Tinbergen home since they also looked after children of parents who spent long periods in the Dutch East Indies, and during World War I, they housed some Belgium and Austrian refugees. Dirk Tinbergen's [17]:-

... love for languages and arts was transmitted onto his children; his occasional outdoor drawing lessons and the walks and bike rides with his children during the summer holidays contributed to the pleasant and intellectual atmosphere which characterized the education. The mother, Jeanette van Eek, personified the order and regularity of the family in terms of both her modest way of conducting the Tinbergen household and her mathematical interest.

Jan attended primary school gaining a certificate stating he was "a most excellent pupil". Then he attended the Hogere Bugerschool in The Hague where his favourite subjects were the sciences and mathematics. This was a special type of school which was designed for children of middle class parents who were aspiring to better their status. These schools allowed entry to the university system after passing additional examinations in Latin and Greek and this Tinbergen did. While at this school Tinbergen's social and political views were formed, partly as a result of the horrors of World War I, which he saw through the eyes of refugees, and partly through his friendship with Tine Johanna de Wit (1902-1991) who later became his wife. He entered the University of Leiden in 1921. In [30] he explained his choice of topics at university:-

I wanted to finish quickly and then to switch to economics. Now you can ask why I chose physics at all, but it was clearly my real interest. I liked physics and mathematics very much and I also felt that that was the thing I was perhaps strongest at, but at the same time I had already come to the conviction that I could probably be more useful to society by being an economist. I think most of the bigger political discussions were economic rather than physical, and so I hoped to get sufficient capability to handle things with mathematics and perhaps take physics as an example of a more developed science than economics.

He studied mathematics and theoretical physics at the University of Leiden and was most influenced there by Paul Ehrenfest. Writing in the newspaper NRC-Handelsblad in 1987 he said of his teachers at Leiden [29]:-

To Ehrenfest I owe a great deal. I studied physics at a time when a number of fascinating persons were there together. Ehrenfest would not instruct as such, as he preferred dialogue. Thanks to him I could participate in discussions with Albert Einstein. Also Kamerling Onnes, Lorentz and Zeeman were present. Being a student in the hands of such teachers, you are very fortunate indeed.

However, Tinbergen also had political interests associated with his left wing views. At university he founded a club for social democratic students and also founded a student newspaper. In fact some of Tinbergen's first publications were articles he wrote for the socialist newspaper Het Volk in which he examined the effects of the economic depression of 1920-22 on unemployment and how the lives of the poor had been affected. While an undergraduate, he became a member of the Labour Party [24]:-

In 1923 I had become a member of the Labour Party and its youth organization; I had come into contact with the poor part of Leiden, not usually known so well by students. In retrospect I wonder whether I would have been clever enough to contribute to modern physics; anyway, my interest went to helping to change society.

After completing his undergraduate degree at Leiden, Tinbergen continued to study at Leiden for his doctorate under Ehrenfest's supervision. However, he had to undertake military service but his political views meant that he was unwilling to do this. He was fortunate in that, only a few years earlier in 1923, legislation had been passed in the Netherlands allowing conscientious objectors to avoid military service. The legislation required that a conscientious objector do government service instead. Tinbergen was assigned to an administrative position at Rotterdam State prison where he was to serve for fifteen months. His father, however, tried to get a better and more satisfying position for his son and, due to his intervention, it was agreed that Tinbergen could transfer to the Dutch government's Central Bureau of Statistics in The Hague. He had already served five of his fifteen months so had only to serve at the Central Bureau of Statistics for another ten months. When he completed these ten months, in 1928, the head of the Bureau persuaded him to take a permanent position there. He agreed, subject to being allowed a break in which to complete work on his doctoral thesis.

Tinbergen submitted his thesis Minimumproblemen in de natuurkunde en de ekonomie Ⓣ in 1929. It combined mathematics, physics and economics. In the introduction Tinbergen thanks Ehrenfest for pointing out to him a topic which could allow him to combine mathematical theories with his political interests. The main part of the thesis is mathematical, studying minimisation problems. Then he gives two appendices, one describing applications of the mathematics to physics, the second appendix giving applications to economics. The importance of this work of Tinbergen was that it was one of the first examples of a new idea in mathematics, namely mathematical modelling. Of course mathematical physics had been studied throughout the history of mathematics but Tinbergen's work saw a new path for the applications of mathematics, where the applications could be to a wide variety of areas.

From 1929 to 1945 he worked as a statistician with the Bureau of Statistics but he also taught in the first few years of the 1930s at the University of Amsterdam. In the Bureau of Statistics, he explained [30]:-

I was responsible for the periodical 'De Nederlandsche Conjunctuur'. It started in 1929, but the War made an end to it. My official responsibility as editor left me quite some freedom. The man supervising my work was in charge of building up something like the London and Cambridge Economic Service, concerned with the cyclical prospects of the Dutch economy.

His influence on the Central Bureau of Statistics is described in [17]:-

Life at the Central Bureau of Statistics at The Hague during the thirties was anything but dull. The problems of unemployment caused by the Great Depression had enforced the call for statistics for policy purposes. Although the Central Bureau of Statistics had been working on business cycle statistics for some time, it was only given its major impulse with the institution of a unit of business cycle research. Tinbergen, who had only just finished his dissertation and entered the staff of statisticians, was given charge of this new unit. Clearly influenced by the German business cycle research institutes in Berlin and Frankfurt, Tinbergen gradually tried to develop an empirical approach to dynamic problems in economics. At the same time he surrounded himself with young engineers, mathematicians and physicists, such as Johannes Bernardus Dirk Derksen, Pieter De Wolff and A Bijl. Together they formed the so called "Q.C." or "Quantitatieven Club", an informal group of young men both socially concerned as well as quantitatively or mathematically oriented. Together with others, such as Tjalling Koopmans, they engaged in small discussion groups evaluating the poverty of contemporary economics and the need for a more rigorous approach.

In 1930 he was one of the founders of the Econometric Society [33]:-

'Econometrica', the journal of the new society, provided a much needed forum for the presentation and discussion of the results of the young science. Here and in the frequent meetings of the Econometric Society, ... Tinbergen made a strong impact both by [his] own contributions and by [his] inspiring personal influence on new cadres of econometricians.

His work on economics in his doctorate had been entirely theoretical, but now he had access to large amounts of data on which to test and develop theories.

From 1933 to 1973 he was professor of economics at The Netherlands School of Economics, Rotterdam. He was appointed to the board of the scientific bureaux of the Dutch Labour Party and he co-authored the Labour Plan in 1935. This plan was based on Tinbergen's mathematically based principles of economics. Gerard Alberts writes in [8]:-

The assumption that these principles of economic rationality might really be made to work was substantiated by Tinbergen one year afterwards in an academic debate on the possibilities of active economic policy. In his contribution to the debate Tinbergen projected a 'quantitative stylising of the Dutch economy' to isolate the important factors and their effects by means of a set of definitions and equations. This "model" of the Dutch economy, as he called it (written with quotation marks at first), would allow one to throw some data into the "mathematical machinery" which would then predict the results.

In the late 1930s Tinbergen worked as a scientific advisor for the League of Nations. They had invited him to investigate statistically which of the business cycles that had been proposed by Gottfried Haberler in his book Prosperity and Depression (1937) did best in practice. This book by Haberler had been written at the request of the League of Nations. Tinbergen was given two years leave of absence from the Central Bureau of Statistics in which to undertake this work. Another book that inspired him was John Maynard Keynes' General Theory (1936). Lawrence Klein writes [18]:-

In private conversations, Tinbergen told me how much he admired the work of Keynes in his 'General Theory' 1936 and that he was so inspired by it that he was trying to provide some empirical substance and use estimated models to implement appropriate policies. It is a pity that Tinbergen's work received such shabby critical treatment by Keynes (in 1939), but being the kind person that he was, he expressed no ill will towards Keynes.

Tinbergen's reply to Keynes was in his paper On a Method of Statistical Research. A Reply (1940), see Kurt Dopfer's paper [13] for details of this controversy.

In 1945, he was appointed as director of the Dutch Central Planning Bureau. Tinbergen later developed other econometric models, in particular he constructed an econometric model of the USA. In 1969 he jointly won the first Nobel Prize for Economics for this first ever macroeconomic model. Perhaps we should quote Tinberg's own words relating to models [28]:-

In an attempt to evaluate what model building has contributed to the theory and practice of economic science I feel that at least we can say that models have had a 'didactic' value. Often in our text books we bring simplified, not to say over-simplified, pictures of reality which nonetheless contribute to making understood some essential features of that reality. ... What I called "didactic value" also stands for 'communication' value. The ability of a planning expert to communicate with politicians and with citizens constitutes an important element in any type of democratic or semi-democratic planning and such communication can be enhanced by relatively simple models. In order not to misrepresent reality, however, there will be a need for a succession of models, as used in planning in 'stages' or, as we now say, multi-level planning. I do think, however, that the utility of models goes beyond their didactic value. They are a real and essential element in the preparation of well-coordinated policies. But they cannot do this job all by themselves. Models constitute a 'framework' or a 'skeleton' and the flesh and blood will have to be added by a lot of common sense and knowledge of details.

His major publications include Grondproblemen der Theoretische Statistiek Ⓣ (1936), Statistical Testing of Business Cycles (1939), Econometrics (1941), On the Theory of Economic Policy (1952), Economic Policy: Principles and Design (1956) and Income Distribution: Analysis and Policies (1975). Of the 1956 work, Charles Lindblom writes [20]:-

[It] is simultaneously a study of some mathematical problems met in constructing models for policy analysis; a demonstration of the application of mathematical models and other systematic, but non-mathematical, methods to a variety of illustrative policy problems; and an exposition of what the policy-making process is and ought to be. On the first, it is excellent; on the second, helpful but puzzling; on the third, I suggest, mistaken.

Gerard Alberts emphasises Tinbergen's impact not only on economics but also on mathematics in [8]:-

Tinbergen, who enjoyed success in both politics and science early in his career, exploited an almost natural opportunity to integrate the two. His career was based on a choice rather than a dilemma, and his work exerted a major impact on both economics and on mathematics. As econometrics grew, it helped to promote a new paradigm for making mathematics useful, mathematical modelling.

His contributions to economics are summed up by Bent Hansen [14]:-

... on no less than six occasions has he brought economics a large step forward. Thus, (i) he was a pioneer in modern economic dynamics; (ii) he helped to establish econometrics; (iii) he is the founder of empirical macroeconomics; (iv) he contributed decisively to create the modern techniques of economic forecasting and prediction; (v) he is the founder of the modern theory of economic policy; (vi) he has contributed significantly to modern development planning in backward countries.

Let us quote Tinbergen himself regarding his personal "value system" [24]:-

I am inclined to indicate sympathy for the underdog or the suffering as one and tolerance as another of the basic elements of my ethical belief. Although a member of a church that strongly emphasized tolerance, I am not sure whether I am religious; but I am sure I am a product of Christianity, interpreted in my own way. My democratic socialist political choice, my European federalist ideal, and my Third World priorities all have that source of inspiration. Looked at from the negative side some of the big evils in this world seem to me to be nationalism and war.

As to hobbies, Tinbergen writes that his main one [24]:-

... is my interest in languages: this I share with my wife and inherited from my parents. Intellectually the comparative part of linguistics is the most interesting part: to compare the diverging meanings the same word has in English and French, or in German or Dutch, for instance "grand"; to compare Italian and Spanish, or Swedish and Danish. ... Anti-hobbies? Yes, I don't like any form of sport and I dislike cars. I have to admit that sometimes I am grateful for a lift: not a consistent attitude!

We end by quoting from Willy Sellekaerts [23]:-

In a neat, simple house, virtually indistinguishable from others on his block in the middle class neighbourhood of The Haviklaan, The Hague, lives one of the world's most distinguished economists, a co-winner of the first Nobel Prize in Economics in 1969, and a man who is known for his gentleness, his modesty, and his selfless dedication to the cause of human welfare. That man is Jan Tinbergen. ... Jan Tinbergen is an unassuming man, who does not trumpet his achievements to the world. He almost never criticizes colleagues. He could earn substantial personal income with his talents, but instead he has chosen to devote himself to the service of others. He does not drive a car, but takes a bus or tram to work. He has been known to thank his undergraduate students for selecting his courses. He has studied many languages, mainly in order to communicate better with those he has worked with in many parts of the world. ... He is fond of drawing. He believes in human dignity. And he lives by that belief.