Γιορτάζοντας τα 60 χρόνια των Θεωριών του Rudolf E. Kálmán και του Piero Sraffa: Τα Συστήματα Τιμών του Πραγματικού Κόσμου είναι Σχεδόν Μη-Ελέγξιμα[Celebrating 60 Years of Rudolf E. Kálmán’s and Piero Sraffa’s Theories: Real-World Price Systems are Almost Uncontrollable]

Using input-output data from the World Input-Output Database (172 Symmetric Input-Output Tables of 43 countries, spanning the period 2000-2014), this paper estimates the degree and rank of Kalman controllability of the relevant Sraffian price systems. The findings suggest that: (i) the degree of controllability is in the range of 10^(–21) to 10^(–18); (ii) for a tolerance of 10^(–4) (of 10^(–2)), the relative numerical rank of controllability is in the range of 7% to 18% (of 4% to 9%); and, therefore, (iii) the price systems are almost uncontrollable. These findings also explain the specific shape features of the empirical price-wage-profit rate curves, which are at the heart of capital theory and, thus, show that the Sraffian theory is not only the most general one but also provides a sound empirical basis.