(Reuters) - Elections are taking place this year in countries home to almost half of the world's population, from Taiwan's general election in January to the U.S. presidential race in November.

The votes come amid growing economic and geopolitical strife, with the Ukraine war, conflicts in the Middle East and rising trade tensions between the United States and China, the world's two largest economies. 

In some countries, there are concerns about the resilience of democracy itself as political discourse has polarized or been warped by disinformation. Many of this year's elections will not be free and fair - or their results will be disputed. 

Half-way through the biggest year for elections in history, here are some common themes that have emerged in Reuters' reporting from around the world:

COST OF LIVING

From the price of green onions in Indonesia to higher fuel bills across Europe, rises in the price of food, energy and other basics have hit the living standards of households across the world. Incumbent governments and leaders are paying for it.

Polling showed that cost of living concerns were a powerful factor in a fall in support for Prime Minister Narendra Modi's party in India, losses suffered by mainstream parties in June's European Parliament elections and the poll rout of Britain's ruling Conservatives.

In Africa, discontent over living standards and unemployment contributed to the ANC's loss of its majority in South Africa's election. Worsening poverty is likely to help shape the outcome of Ghana's December vote to succeed President Nana Akufo-Addo. 

Polling ahead of the U.S. election suggests voters are similarly unimpressed with President Joe Biden's efforts to improve their livelihoods, with many Americans feeling their living standards are falling despite strong headline economic data. One outlier: In Mexico, the ruling MORENA party emerged the winner after offering ample subsidies to low-income voters.

While economic policymakers say there are signs that inflation is returning to normal, they warn it has not yet been fully tamed and many economies remain fragile.

"A number of pressure points could throw the global economy off track," Agustin Carstens, head of the central bank umbrella group the Bank of International Settlements (BIS), warned in June.

GREEN TRANSITION

With the cost of living uppermost in many voters' minds, climate change action has often been crowded out of election campaigns - even as global temperatures break new records and death tolls from extreme heat climb.

While surveys show Europeans still support ambitious action on global warming, the debate there has focused on the perceived cost to livelihoods, with farming and other lobbies stepping up calls for an easing of net-zero policies. 

In the EU elections, ecologist Greens shed most of the gains made five years earlier. In Britain, Labour dropped a 28-billion-pound green investment pledge ahead of the July 4 general election, saying the country could not afford it, while their Conservative rivals described themselves as "on the side of drivers", attacking low-traffic and low-emission schemes. 

The biggest challenge to the green transition may come from the United States, with Donald Trump campaigning on policies supporting continued fossil fuel use. It remains to be seen how much of Biden's Inflation Reduction Act (IRA) green subsidies stay in place in the event of a Trump victory.

SWING TO THE (FAR)RIGHT? 

The cost of living crisis has led to rising support for far-right movement in Western countries with a mix of anti-immigration and nationalist policies, often unfunded economic spending plans and populist rhetoric attacking global elites.

Back in March, Portugal's Chega party quadrupled its seats in parliament to become the country's third-largest party. Three months later, its far-right, eurosceptic peers across Europe made gains in elections to the European Parliament.

In France, Marine Le Pen's National Rally failed in elections on Sunday to achieve the majority they were coveting but became the largest single party in a hung parliament that now risks plunging Europe's second-largest economy into policy paralyis.

In Britain, the anti-immigrant, nationalist Reform Party won over four million votes, contributing to the collapse in support for the ruling Conservatives even if Britain's first-past-the-post electoral system meant it only won a handful of seats.

Austria's Sept. 29 election will be closely watched, with polls showing the far-right Freedom Party (FPO) leading rivals after it ranked first in European Parliament elections.

In the United States, Trump has made immigration one of his top domestic campaign issues, declaring he would carry out mass deportations, end birthright citizenship, and expand a travel ban on people from certain countries.

Mohit Kumar, chief economist for investment house Jefferies, noted that immigration as an election theme was hottest in precisely the large Western economies whose ageing populations were creating labour shortages.

"Economically we need immigration but the political dynamics are shifting away from immigration," he said.

DEBT AND ELECTION LARGESSE

With economic hardship so prevalent, many politicians are offering to spend big and cut taxes in a bid to win power - at the risk of adding to global debt already at record levels after huge post-pandemic stimulus packages in rich-world economies.

Credit rating firm S&P Global has warned the United States, France and other Group of Seven (G7) governments were unlikely to halt rises in their debt "at the present stage in their electoral cycles". 

The BIS annual report in June said an election year like this brought an "especially high" risk of fiscal expansion that could complicate efforts to bring inflation down to target.

Budget watchdogs in Britain and France - two countries struggling to balance their budgets - noted that many spending pledges were either unfunded or unrealistically costed.

Trump has pledged to keep in place a broad 2017 tax cut that he signed while in office, and his economic team has discussed a further round of cuts beyond those enacted in his first term.

Biden, meanwhile, proposes raising levies on businesses and rich individuals, while vowing not to increase taxes for households earning less than $400,000 a year and to assist low- and middle-income Americans with childcare costs. U.S. federal government currently has more than $34 trillion in debt.

Such levels of debt are seen making the global economy more vulnerable to financial shocks and the International Monetary Fund has urged governments to reduce their borrowing.

"Unfortunately, fiscal plans so far are insufficient and could be derailed further given the record number of elections this year," its chief economist Pierre-Olivier Gourinchas said in a recent blog.

DEFENCE AND SECURITY 

As geopolitical tensions rise, defence and security matters have been prominent in a number of election campaigns so far this year - particularly in countries near the hotspots.

In February, Finland elected as president Alexander Stubb, who campaigned on the previously non-aligned country fully participating in NATO and allowing the transit of nuclear arms through it. Incumbents in Lithuania won an election dominated by concerns over Russia and calls for higher defence spending.

Taiwan's presidential and parliamentary elections on Jan. 13 focused around arguments on how best to deal with China, which views the island as its own territory. The ruling DPP party secured the presidency for a third term as its candidate vowed to safeguard Taiwan from intimidation while emphasising the need for dialogue with Beijing.

In the United States, Democratic voters' anger over Israel's military action in Gaza - and over Biden's continued support of Israel - has emerged as a major vulnerability for him. American views on the conflict have broken down along party lines with Republicans largely supporting Israel.

While Biden voices unwavering support for NATO, Trump has said that if he is returned to the White House, America would fundamentally rethink NATO's purpose. He has also asserted without evidence that if elected he would end the conflict in Ukraine before even taking office. On that, Biden has retorted that Trump has "no idea what he's talking about".

DEMOCRACY AT STAKE?

Pro-democracy watchdogs estimate that nearly three-quarters of the world's population live in autocracies. Observers and human rights groups have signalled concerns about the fairness of elections this year in Bangladesh, Azerbaijan, Belarus, Cambodia, Iran and Russia. Votes in Algeria and Uzbekistan face similar questions.

Modi's electoral setback has been hailed by some commentators as proof of the resilience of its democracy. There was relief at the peaceful handover of power in Senegal in March after moves by the incumbent to delay the vote triggered protests. 

Democracy's biggest test this year may, however, be in Washington.

Trump refuses to commit to accepting the election results or to rule out possible violence around the Nov. 5 contest. He is already laying the groundwork to contest a potential defeat.

"We should be quite worried," Steven Levitsky, political scientist and professor of government at Harvard University, told a Brookings think tank event in June.

"A democracy cannot survive if one party in a two-party system is not committed to playing by the democratic rules of the game."

(Graphics by Sumanta Sen and Anand Katakam; Editing by Simon Robinson and Daniel Flynn)

By Mark John, Sumanta Sen and Anand Katakam