Herman Wold

Herman Ole Andreas Wold (25 December 1908 – 16 February 1992) was a Norwegian-born econometrician and statistician who had a long career in Sweden. Wold was known for his work in mathematical economics, in time series analysis, and in econometric statistics.

Herman Wold
Born	(1908-12-25)25 December 1908 Skien, Norway
Died	16 February 1992(1992-02-16) (aged 83)
Nationality	Swedish
Alma mater	University of Stockholm
Known for	Wold's theorem MA(${\displaystyle \infty }$) representation of stationary stochastic processes Wold decomposition (Operator theory) Cramér–Wold theorem Time series analysis Utility theory Consumer demand Latent variable Structural equation models Consistent least squares estimation of recursive triangular systems Causal inference in observational studies Partial least squares regression
Scientific career
Fields	Statistics Econometrics
Institutions	Uppsala University
Doctoral advisor	Harald Cramér
Doctoral students	Sten Malmquist Peter Whittle Karl Jöreskog

In mathematical statistics, Wold contributed the Cramér–Wold theorem characterizing the normal distribution and developed the Wold decomposition in time series analysis. In microeconomics, Wold advanced utility theory and the theory of consumer demand. In multivariate statistics, Wold contributed the methods of partial least squares (PLS) and graphical models. Wold's work on causal inference from observational studies was decades ahead of its time, according to Judea Pearl.