I am a PhD-level consultant designing algorithms and numerical simulations for investing, personal finance and financial planning. I have over ten years of international experience in mathematical modeling and numerical simulations.
I have a doctorate degree from the University of Michigan. I co-authored 15 scientific articles of numerical modeling and computer simulations. I am also the author of the book "Votre argent mérite de vous rapporter plus" (http://mathieu.bouville.name/fr/placements/livre/) as well as of articles on investing and personal finance for a broad audience at http://mathieu.bouville.name/en/finance/articles/.
I am working on quantifying objectively after how many years an equity investment (S&P 500) starts behaving differently, i.e. when 'the long term starts'. Indeed the claim that the stock market is an investment for the long term is as common as empirical, robust thresholds for it are rare. 'Recommendations' tend to look something like 'the time horizon for stock investments should be no less than x', where x can be 5 years, 10 years, any number. Read the article "Long-term stock investments should last three decades" (http://ssrn.com/abstract=2739602).
I also designed and implemented a personal finance simulation tool which calculates the long-term evolution of your wealth based on those of your income and expenses. The difference between the two is invested in a stock–bond portfolio and the possible evolution of your wealth is calculated with Monte Carlo simulations (see http://mathieu.bouville.name/en/mathematical-modeling/Monte-Carlo-simulations.html#financial-planning) to then be plotted.
I modeled stock–bond portfolios (github.com/m-bouville/investing-by-numbers), looking for the optimal strategy for long-term investments.