LISBON — Education policy isn’t the Portuguese government’s strong suit. There have been 28 education ministers since 1974. Only half of the country’s 25-to-34 year-olds have successfully completed high school; dropout rates are among the highest in Western Europe.

In the 1990s, in an effort to improve the quality of education, the government decided to consolidate public schools into clusters called agrupamentos, each to be overseen by one central administrative authority.

Two decades later, in 2010, the Education and Science Ministry announced plans to merge elementary, middle and high schools some more, into mega-agrupamentos, still-bigger groupings.

The whole process has been a slowing-moving disaster.

The point of the initial policy was to better monitor the performance of individual schools by tightening oversight. But against a backdrop of economic crisis, the purpose of the more recent consolidation was simply to cut costs — and it has gone too far.

There are now 237 mega-agrupamentos nationwide: 87 created in 2010 and 150 last year. Each one comprises between three and 10 schools; students range from 5 to 22 in age. In Lisbon and Vale do Tejo, five of the 18 new groupings have more than 3,000 students.

According to Education International, an international consortium of teachers’ unions, 23,000 teachers retired in Portugal over the past six years, but only 396 new ones were hired in their place. As a result, in addition to having to rove between different schools to teach the same subject, instructors in mega-agrupamentos are increasingly having to teach other subjects as well.

Last week, I visited to the Lumiar Secondary School in northern Lisbon, headquarters of a mega-agrupamento of seven schools roughly five kilometers apart. There used to be 13 principals running all those schools; now there are five. The total student population has grown from about 1,500 to more than 2,000.

The director of the mega-agrupamento, Joao Martins, complained about having to do too much with too little. The whole point of grouping schools together, he said, was to better monitor the classroom. But the system is so sprawling that has become virtually impossible. Directives from the center don’t always make it to all the teachers throughout the mega-agrupamento. Conversely, teachers’ observations don’t always make it back up the chain.

Teachers and administrators also say they are ill-equipped to rein in the escalating violence in schools and need to call for assistance from the directors of the mega-agrupamentos, who are often far.

“I can see my students drifting away,” said Isabel Louça, a Portuguese and history teacher in Lisbon. “Some come to school hungry. Others are upset by what’s going on at home. Families are struggling right now. The kids are acting out, and we can’t respond.”

Despite these problems, earlier this year the Education Ministry announced the creation of 67 more mega-agrupamentos. Several of them will be bigger than the previous government said was manageable when it crafted the policy in 2010. Educators were largely kept in the dark as the new plans were hatched.

Consolidating resources once seemed like a plausible way to improve education in Portugal. Now it’s an excuse for cutting corners. As Elisa Rocha, assistant principal at Lumiar, told me, “The ministry in charge of education is actually the Finance Ministry.” And the more the government tries to lower its education tab, the higher the human cost.