If you’ve got a stake in the sharemarket, you’re probably doing quite well today. That’s because the markets were pleased with the results of yesterday’s upper house election in Japan, which was a big victory for conservative prime minister Shinzo Abe.

Abe’s Liberal Democratic Party took power at the end of last year when the Democratic Party of Japan was turfed out after one term in office. As I said at the time, voters seemed “unenthusiastic about any of the choices on offer”, after each party in turn had failed to make an impression on Japan’s woeful economy. But Abe still lacked a majority in the upper house, the Sangiin (House of Councillors, or Senate).

Japan’s Senate is very similar to Australia’s: it’s about half the size of the lower house, with half the senators elected every three years for threesix-year terms. And it has a similar range of powers, so a government majority is not essential but is very useful. Unlike Australia, however, the elections are not usually held together, so there’s often a sort of by-election effect where voters can take a shot at the government without actually putting the opposition into power.

That’s how it was in 2010, when the then DPJ government lost its (tenuous) Senate majority and the LDP picked up 13 seats. But this time around, the Abe government is still enjoying a honeymoon. Unofficial results show that the LDP and its ally, the New Komeito Party, won 76 of the 121 on offer yesterday, while the DPJ managed only 17.  The government will enjoy a working majority in the new Senate, although not the two-thirds majority that would enable it to revise the constitution.

The Asahi Shimbun reports Abe saying “I believe we received the votes of those who wanted a political sector that could make decisions and that would push forward economic policies under a stable government.”

Just as with last year’s lower house vote, the seat totals don’t tell the whole story, because the system is weighted in favor of rural voters – who tend to support the LDP. I can’t find any vote totals yet (if you read Japanese you could try here), but in 2010 the LDP won 39 of the 73 prefectural seats (there is also a PR component) with only a third of the vote. The DPJ actually had more votes, but won eleven fewer seats.

A subsequent supreme court judgement found that the malapportionment in both houses was so great that it violated the constitution, but it declined to void the election or order any immediate remedy. Only minor changes have been proposed since, and it is not even clear that they were in effect in time for this election. As in many countries, no-one really wants to tell rural voters that they are not as special as they think they are.

So Abe now has a clear run. Stable government is not a bad thing, but nor is it an unmixed blessing. It can be particularly dangerous when a government imagines itself having more popular support than is really the case (on one view that was the problem Mohammad Morsi had in Egypt).

I don’t pretend to know whether Abe’s economic policy is the right way to go or not (certainly nothing else much has worked over the last twenty years or so, so it’s probably worth a try). But some of his other moves – boosting military spending and increasing tension in the East China Sea – seem positively dangerous.

A fractious Senate might have helped to rein him in a bit. That particular brake is now off.