In India, political ads on Facebook are viewed overwhelmingly by men over women, according to information now available on the social network’s Ad Library.

This may suggest that political parties are attempting to disproportionately target men, although experts told Quartz that other explanations are also possible. The lack of clarity around the reasons for this gender skew underscores how targeted advertising is one of the murkiest parts of Indian electoral politics today.

Facebook’s Ad Library is an up-to-date archive of advertisements on the platform that are political or related to “national importance.” The resource was made publicly accessible for Indian ads on Thursday, as part of Facebook’s transparency efforts ahead of the country’s upcoming parliamentary election.

Each entry in the library shows how many impressions an ad received, and an approximate amount of money spent on it, besides the age, gender, and location-wise breakdown of who saw it.

A Quartz analysis shows that a vast majority of ads posted by pages of key political parties were seen by audiences that are heavily male. The gender skew at play, in which men often outnumber women nine to one, or more, is far starker than the overall gender divide on Facebook, which was in 2016 reported to have a 24% female user base in India.

Here’s what we saw in an analysis of the ads on the library from three major national parties: the governing Bharatiya Janata Party, the primary opposition party, the Indian National Congress, and the Aam Aadmi Party, which is in power in Delhi.

BJP

Three pages seem to be sharing a bulk of the BJP’s campaign content on Facebook: the party’s official page, a party volunteer organisation called Nation with Namo, and a recently launched campaign for the election, Bharat Ke Mann Ki Baat.

Up to 81% of the BJP’s recent advertisements on the three pages, combined, were found to have been viewed by a “heavily male” audience (defined, for the purposes of this analysis, as a group of 90% male Facebook users, or more).

Quartz tabulated results for the most recent 60 ads run by each page; if a page had fewer than 60 ads, they were all analysed.

Data: Facebook Ad Library ["heavily male" is defined as an audience of 90% males or more]

This gender skew manifested itself in ads that, for example, the ad library showed as having reached a minuscule percentage of women:

Or sometimes, no women at all:

One ad that the BJP page has often posted tended to draw more female viewers than others: An advertisement about how much prime minister Narendra Modi has done for the nation’s daughters. But even these were not always seen by many female users. Ads that depicted Modi’s goodwill towards farmers or soldiers received even fewer female views, if any at all.

AAP

Up to 56 of the 60 most recent ads on the official AAP Facebook page were shown to heavily male audiences.

Data: Facebook Ad Library ["heavily male" is defined as an audience of 90% males or more]

A total of 26 of these ads were shown exclusively to men.

Congress

Congress’s official Facebook page seems to have learned quite a bit about how to target women this month. While posts from January and prior show many heavily male audiences, this month the party seems to have rejiggered its tactics and is drawing much larger female audiences than it was earlier, routinely surpassing the 10% cutoff.

However, it does not seem to be applying these tactics on other pages where it seems to be advertising a lot—those of its student wing, the National Students’ Union of India, and its youth wing, the Indian Youth Congress.

When averaging the ad audiences of the Indian Youth Congress, the National Students’ Union of India, and the Congress’s official page, up to 92% of the ads were seen by heavily male audiences.

Data: Facebook Ad Library ["heavily male" is defined as an audience of 90% males or more]

Almost half the ads on these three pages had not been viewed by a single woman.

Through the youth wing and student wing pages, Congress posts many ads about recruiting new party volunteers. This could have more serious ramifications than usual: these particular ads being seen almost exclusively by men may even affect the gender makeup of future party volunteers.

Queries have been sent to the heads of the social media teams of all three parties; the copy will be updated as and when they respond.

Possible reasons

Sketching this trend, however, is much easier than explaining it. A possible explanation for the massive gender skew in ad viewers is that campaign managers could be asking Facebook to specifically target male audiences, like they might ask to target people who live in a particular area, or are of a particular age.

There may be a strategic reason for this: “The more precisely you can target your audience, the more likely you are to get a high return on your investment,” Ben Nimmo, a senior fellow at the Atlantic Council’s Digital Forensic Research Lab, told Quartz. “So if you think that your advert will be of no interest to women or people over the age of 45, you exclude them from the criteria.”

But, Nimmo was careful to note, that, in the absence of back-end information on what type of targeting the parties had requested, this is, at best, speculation.

Another explanation could be that parties are choosing to direct ads towards audiences that “like” certain other Facebook pages, which also happen to be overwhelmingly liked by men. For example, if a fan page for the Indian Army happens to have 95% male fans, “that ad is approximately going to be served to 95% male audiences,” a digital marketing professional who has worked with political parties told Quartz.

Another factor is “the kind of activity level Indian Facebook audiences have in the kind of areas (politicians are) targeting,” the marketing professional continued. For example, in tier two and tier three cities, “Facebook penetration among females is even lower…the traffic that the advertisers are relying on might not be as diverse as they were hoping for.”

Of course, regardless of whether the initial targeting of men was intentional, the fact that most of the pages Quartz studied showed a nearly entirely male audience over a period of months may suggest that the parties are not doing all they can to reach wider audiences on Facebook.

This data may also point towards the need for parties to move away from Facebook if they wish to digitally campaign to women, whose turnout in some recent state elections has even exceeded men’s. By the time mobile phones became readily accessible to working-class women, the marketing professional said, “Facebook was not as useful to them as, say, a WhatsApp is, as YouTube is. Their Facebook timeline has now been replaced by numerous WhatsApp groups.”

Facebook, he said, “played a much larger role last time than it is going to in the next elections. The more important partner is going to be WhatsApp, regional apps, and apps like TikTok, which are gaining massive popularity.”

This article first appeared on Quartz.