Leontief sided with campaigners for academic autonomy, freedom of speech and in support of Pitirim Sorokin.

In 1925, he was allowed to leave the USSR, mostly because the Cheka believed that he was mortally ill with a sarcoma, a diagnosis that later proved false.

[8] He continued his studies at the Friedrich Wilhelm University in Berlin and, in 1928, earned a Ph.D. degree in economics under the direction of Werner Sombart, writing his dissertation on The Economy as Circular Flow (original German title: Die Wirtschaft als Kreislauf).

In 1949, Leontief used an early computer at Harvard and data from the U.S. Bureau of Labor Statistics to divide the U.S. economy into 500 sectors.

Input–output was novel and inspired large-scale empirical work; in 2010 its iterative method was recognized as an early intellectual precursor to Google's PageRank.

[17][18][19] Leontief used input–output analysis to study the characteristics of trade flow between the U.S. and other countries, and found what has been named Leontief's paradox; "this country resorts to foreign trade in order to economize its capital and dispose of its surplus labor, rather than vice versa", i.e., U.S. exports were relatively labor-intensive when compared to U.S. imports.

To that end, Wassily Leontief did much to make quantitative data more accessible, and more indispensable, to the study of economics.

The Global Development and Environment Institute at Tufts University awards the Leontief Prize in Economics each year in his honor.

The trouble is caused, however, not by an inadequate selection of targets, but rather by our inability to hit squarely on them, ... by the palpable inadequacy of the scientific means with which they try to solve them.

The weak and all too slowly growing empirical foundations clearly cannot support the proliferating superstructure of pure, or should I say, speculative economic theory.... By the time it comes to interpretations of the substantive conclusions, the assumptions on which the model has been based are easily forgotten.

... A natural Darwinian feedback operating through selection of academic personnel contributes greatly to the perpetuation of this state of affairs.