The board of KIVI Region North Holland has the pleasure of inviting you to attend a lecture to be given by Guus van Ditzhuijzen on the occasion of his retirement as a board member of our regional section.

The title of his story naturally begins with Joseph explaining this to Pharaoh, and with the current and upcoming crises is very topical again... After studying Mechanical Engineering (majoring in Measurement & Control Engineering), Guus spent his working life at Hoogovens. Both professionally and in his spare time, Guus has always worked with and thought about complex mathematical models with great interest - also in connection with music, as he explained to us so captivatingly during the 16 January 2019 New Year's Meeting.

For his farewell speech at Hoogovens, Guus made a frequency analysis of steel production. This is highly cyclical and after subtracting the long-term curve, a duration of 13-15 years comes out significantly. So, interesting business cycle waves.

The literature also pays a lot of attention to all kinds of cycles: Kondriateff Waves, Kuznet Swings, Juglar & Kitchin Cycles, etc.

After an introduction, Guus will present a number of frequency analyses of economic movements.