Valkov's theory builds on earlier ideas from Jevons (1875), Garcia-Mata (1934), and the Foundation for the Study of Cycles, but he elevates them with rigorous modern statistical methods and an extraordinary historical dataset covering twelve major economies, including the United States, United Kingdom, Russia, and China—both before and after industrialization.
At the heart of Valkov's paper is the HelioEconomic Leading Index (HELI), a composite indicator that combines smoothed Wolf sunspot numbers (inverted and appropriately lagged) with macroeconomic variables such as unemployment rates, GDP growth, and industrial production. Spectral analysis, Granger causality tests, and principal component methods show that the HELI index explains approximately 78% of the variance in global business-cycle turning points over nearly three centuries—a level of explanatory power rarely achieved by conventional leading indicators. The alignment is striking. Major economic peaks repeatedly occur near every fifth solar maximum (for example, the Roaring Twenties, the mid-1960s–early-1970s boom, and the 2014–2020 expansion), while the deepest depressions and recessions cluster around prolonged solar minima (the 1930s Great Depression, the early 1980s double-dip, and the 2008–2009 Global Financial Crisis all fit the pattern with remarkable precision).
based on psychological excitability: Minimum (3 years), Growth (2 years), Maximum (3 years), and Decline (3 years).
The model forecasts an accelerating contraction phase leading into a major multicycle trough centered on the early 2030s—precisely the period when the next solar minimum is expected. Mainstream macroeconomics remains deeply skeptical of any strong exogenous pacemaker for business cycles, and critics will rightly point to risks of overfitting and the indirect nature of causal mechanisms. Yet, the sheer scope of the evidence—280 years, twelve diverse economies, consistent performance across radically different institutional regimes—makes the paper impossible to dismiss lightly. Whether helioeconomics ultimately gains broad acceptance or remains a heterodox curiosity, the HELI index has already demonstrated superior long-range forecasting ability compared with traditional indicators. The Sun, it turns out, may have been conducting the global economic orchestra far more faithfully than ever realized.
