MANILA, Philippines — The government’s tax effort likely rose to 12.3 percent of the country’s gross domestic product last year from 12.1 percent a year ago, preliminary data from the Department of Finance showed Thursday.

The fiscal authorities credit the improving revenue collection performance of the country’s two main tax agencies, the Bureau of Internal Revenue (BIR) and Bureau of Customs, for the increase in the country’s tax effort.

Tax effort, one of the closely watched economic indicators, used to gauge efficiency of tax collection, is computed as a percent of the country's gross domestic product.

To manifest efficiency in tax collection, a government should be able to increase the amount of taxes it collects every time income levels grow.

The tax effort of the BIR alone improved from 8.23 percent to 9.2 percent, which is being attributed to the implementation of administrative measures and to its Run After Tax Evader (RATE) program.

The Bureau of Customs’ tax effort also rose from 2.6 percent to 2.66 percent.

The BIR and the Customs are the government's biggest revenue earners, together composing more than 80 percent of state revenues.

Fianance Secretary Cesar V. Purisima earlier said that the government registered its highest revenue take in over a decade in 2011 despite the absence of new taxes and asset sales.

Purisima said in a speech that government revenue increased by more than 13 percent last year from P1.093 trillion it raised in the previous year.

The BIR, the government’s main tax agency, has not yet released its collection performance in 2011.

Meanwhile, the Bureau of Customs, the government’s second largest revenue generating agency, reported that it missed its collection target for last year, raising only P263.85 billion, significantly lower than the P320 billion goal.

Budget and Management Secretary Florencio B. Abad earlier said that the government’s fiscal deficit probably widened in December as the government increased spending to bolster an economy.

Abad said the emerging budget deficit last year was P191.6 billion. The 11-month shortfall was P96 billion, indicating the gap doubled in a month.

The National Statistical Coordination Board (NSCB) had reported that the country’s gross domestic product grew 3.7 percent last year, slower compared with 7.6 percent in incurred in the previous year.