### Trygve Haavelmo was a Norwegian economist and professor who was awarded the Nobel Prize in Economic Sciences in 1989 for his contributions to the discipline. He is thought to be the first Nobel Prize winner for econometric research. He lived most of his life in relative anonymity until he was awarded the Nobel Prize and catapulted into prominence, especially in his native Norway. Following that, he did everything he could to avoid notoriety and public debate. He was also a remarkable instructor who lasted two generations and had a huge influence on subsequent Norwegian economists. His students looked up to him as a role model, and many of them wished to follow in his footsteps. Throughout his life, he inspired a large number of students to pursue economics as a career. His significant interest in economics and intelligence resulted in novel approaches to the development of economic difficulties. He pioneered econometrics, emphasizing the role of mathematics and statistics in the development of economic ideas. He has built a notable position for himself in economics based on his work. Read on to learn more about his life and work.

## Childhood and Early Years of Trygve Haavelmo

Haavelmo was born in 1911 in Skedsmo, Norway, near Oslo. He studied at the University of Oslo in 1930 after completing his elementary school and finally graduated with a degree in economics. Haavelmo joined Ragnar Frisch’s Institute of Economics as one of his assistants after Frisch recommended him. In 1935, he was promoted to the position of chief of calculations at the institute. The following year, he attended London University College’s statistics department alongside Jerzy Neyman and Egon Pearson. In the year 1938, he went on a study tour to Berlin, Geneva, and Oxford.

He was a lecturer in Statistics at the University of Aarhus from 1938 until 1939.

The following year, he was awarded a scholarship and embarked on a study trip to the United States, which he expected to last no more than 12 years. He spent his time in the Cowles Commission during his visit. He was awarded the Rockefeller Fellowship and spent a year traveling and working at Harvard. He worked as a statistician at Nortraship’s office in New York from 1942 to 1944, and then as a commercial secretary at the Norwegian Embassy in Washington, D.C. for another two years. During this time, he worked on and published his most famous work on econometrics, for which he is still well-known.

## Later the Years

He then returned to Oslo and began working in the trade department at the University of Oslo, where he remained until 1979. During his time as a professor, his research interests shifted to economic theory, and he wrote a book titled ‘A Study in the Theory of Economic Evolution,’ which was praised for its methodological innovation. It was a good examination of a country’s economic underdevelopment in comparison to other countries.

In econometrics, his probabilistic method introduced a probability basis to the analysis of economic relations. He is most recognized for his work on problem identification and economic equation analysis. His views and ideas constituted a significant part of the research activities of the Cowles Commission in Chicago, where he worked in 1946. He was the chief of a division within the Norwegian Ministry of Finance, where he was in charge of organizing and implementing the postwar planning system. He was also interested in macroeconomic theory. ‘A Study in the Theory of Economic Evolution,’ published in 1954, pioneered a novel approach to economic development difficulties.

He released a book titled “A Study in the Theory of Investment” in 1960, which dealt with the supply side of the capital goods market. To some extent, each of these efforts gained him credit and a reputation.

## Major Projects of Trygve Haavelmo

Supplementary Confluent Relations Method, 1938

The Inadequacy of Comparing Theoretical Solutions with Observed Cycles to Test Dynamic Theory, Statistical Analysis of Business Cycles, 1940 1943

A System of Simultaneous Equations and Its Statistical Implications, 1943

In econometrics, the probability approach is used. A Balanced Budget’s Multiplier Effects, 1944 1945

The Marginal Propensity to Consume and Family Expenditures, Methods of Measuring the Marginal Propensity to Consume, published in 1947. Statistical Analysis of Food Demand: Examples of Simultaneous Estimation of Structural Equations, co-authored with M.A. Girshick, published in 1947. 1947

The Marginal Propensity to Consume and Family Expenditures, 1947 The Interdependence of Agriculture and the National Economy: Quantitative Research in Agricultural Economics, 1947

Involuntary Economic Decisions as a Concept,

1949

A Remark on Investment Theory, 1950

The Concepts of Modern Inflation Theories, 1951

The Theory of Economic Evolution: A Study, 1954

The Econometrician’s Contribution to Economic Theory Advancement, Econometrica, A Study in the Theory of Investment, published in 1958. Mathematical Models, 1960 Business Cycles II, Gossen’s Variation on a Theme, 1968 What Can Static Equilibrium Models Tell Us?, (Swedish), 1972. 1974

The Welfare State and Econometrics, 1990

## The Probability Approach of Haavelmo

One of his most important studies, the probability method, is regarded as one of his greatest contributions. The method addresses the issue that existing economic data should be viewed as “a sample selected by nature” that is guided by an unnoticed reality. He stated that economic theories can be tested by framing the theoretical model to statistical relationships.

The method implies that the relationship between theory and reality is analogous to the relationship between observable facts and reality. This method yields a clear statistical theory that the theoretical relationships are more or less true if we effectively state that we have “reproduced” another “natural drawing” from reality.

## Significant Contribution

His key contributions were two works, one of which demonstrated the statistical consequences of simultaneous equations and the other of which firmly established probability theory as the foundation of econometrics. His brief stay in the United States culminated in the publication of the book ‘The Probability Approach in Econometrics.’ In it, he outlined many of the tactics employed in economics, but he said that they were all false. The interaction of many economic ties had not been recognized in economics, and economic laws were not rigorous.

His significant contribution was the invention of a novel mathematical statistics-based approach to approximating economic interactions. Following that, he pursued his interest in economic theory further. His work, ‘A Study in the Theory of Economic Evolution,’ looked into the factors of a country’s economy being underdeveloped in compared to others. The ‘Balanced Budget Multiplier Theorem,’ which was a new technique in business cycle theory, was his contribution to economics.

The ‘Theory of Investment’ was another significant contribution. In his work ‘A Study in the Theory of Investment,’ he coined the demand for actual capital, as well as the indisposition to modify real capital. His studies and publications on investment behavior and environmental economics have sparked additional research and the development of new theories.

## Death of Trygve Haavelmo

Trygve Haavelmo died on July 28, 1999, in Oslo, Norway, at the age of 87.

## Accolades & Awards

For the illumination of the probability theoretical underpinnings of econometrics and the studies of co-occurring economic structures, Haavelmo received the Nobel Prize and the Sveriges Riksbank Prize in Economic Science in 1989.