Jona was born in Utrecht (NL) in 1954 and emigrated to Israel in 1972, where he received his Ph. D. in Demography in 1988. His dissertation is on the historical demography of two eighteenth-century Dutch villages. Jona now teaches demography and one course in genealogy at the Department of Sociology and Anthropology, the Hebrew University. He has published several articles on genealogy in Dutch and English. Even those who are not related to anyone mentioned in these publications, might still find the methodological section in these publications worthwhile reading.
1995: "Age overstatement among European Jews", Avotaynu XI, pp. 30-31.
2002: "Genealogy of Schellekens: [in the village of] Gilze 1565-1762", Gens Nostra 57, pp. 64-78 (in Dutch).
2003: "Descent from Rashi: a mythological charter?" and "Descent from Rashi: response to Rosenstein", Avotaynu XIX.
2004: "The first generations of Kiek in [18th-century] Hamburg", Gens Nostra 59, pp. 81-86 (in Dutch).
2006: "The family of rabbi Yehuda Ashkenazi", Sharsheret Hadorot.
Forthcoming: "Every other generation: [the first name] Elkele", Gens Nostra (in Dutch).