In 2010, presenting his Doctoral Thesis "The Impact of Fiscal Policy on the Economy", Oļegs Tkačevs got a PhD in Economics from the University of Latvia. In 2005, Oļegs Tkačevs got a Master's Degree in Economics from the University of Latvia and a Diploma in European Studies from the University of Southern Denmark, Odense. In 2001–2003, he worked as a lecturer at Riga Business Technical School. Oļegs Tkačevs started his career at the Bank of Latvia in 2004 as an economist of the Monetary Policy Department. He is the author of various research publications; as of 2007, he delivers a course of lectures "Public Finances" (initially at the University of Latvia, at present – at the Stockholm School of Economics in Riga).

Oļegs Tkačevs' responsibilities include analysing Latvia's fiscal policy, forecasting budgetary indicators, participating in the Working Group on Public Finance of the Monetary Policy Committee of the European System of Central Banks as well as doing research in the area of fiscal policy. Oļegs Tkačevs represents the Bank of Latvia at the meetings with international lenders on fiscal policy issues.