The transfers are a function, not a measure of size. The clerical costs of the transfers are included in the purchases. The graph over-estimates government consumption by lumping all Grants with Purchases. The size of the federal government as measured by its purchases relative to the nation's production has been decreasing erratically but persistently since about 1954. The rate of growth has been somewhat slower since 1983.
Transfers are sensitive to the state of the economy, rising during recessions.
The principal money role of the U.S. federal government is now the transfer of money from some people to other people. Its own purchases are of lesser amount. This operation moves money into the hands of those more likely to spend it. Finally, as confirmation of the decreasing size of the federal government, the last graph shows federal employment relative to total U.S. employment to have been in a steady and rapid decline since 1970, in agreement with the fall in non-transfer expenditures. The increase in state and local government employment is also shown.