Tuesday, December 30, 2014

Are you more likely to win 4D on your birthday, with your birth date?

In the 4D lottery, you select a 4-digit number, from 0000 to 999. If your number is amongst the 23 numbers chosen in a thrice-weekly draw, you win a cash prize.

 Feeling lucky during your birthday? Should you bet with your birth date (e.g. 1501 for 15 Jan)?

Monday, December 29, 2014

Are the 7 long weekends in 2015 truly a "bumper crop"?

A long weekend occurs when a public holiday falls on a Monday, Friday, or Sunday (when a public holiday falls on a Sunday, Monday is also a holiday). This makes three out of seven days, which means that the odds of a long weekend are pretty high, at slightly under half.

For 2015, we have long weekends on 7 out of the 11 public holidays, a "bumper crop", according to the Straits Times. Is this truly a long weekend bonanza, or something closer to the theoretical average?

Wednesday, November 19, 2014

Showdown: PS4 vs Xbox One

It has been a year since the PS4 and Xbox One were released. The PS4 has sold 13 million units, while the Xbox One is lagging behind with 10 million sales. Is the PS4 really the better console?

Wednesday, November 5, 2014

Left-digit bias in the diamond market (or how to get your money's worth when buying a diamond)

Suppose your favourite cup of coffee costs $2.50, but its price rises to $3.00. Now suppose that the same cup of coffee costs $2.40, and its price increases by the same amount, 50 cents, to $2.90.

Many would feel more upset over the first scenario, even though the price increases by the same amount in both cases. The jump in the dollar digit, or the leftmost digit, makes it seem that the increase is greater. This is known as left-digit bias.

Friday, October 31, 2014

Which mobile plans offer the best value?

There are currently 20 mobile phone plans with data, from Singtel, M1, and Starhub. The plans are quite diverse - some offer more data, others more talk time, and some free incoming calls. Which offers the best value?

Thursday, October 9, 2014

The most (and least) successful online petitions in Singapore

Getting people to support a cause used to be a difficult, resource-intensive process. Today, anyone can start an online petition, and quickly mobilise thousands of like-minded people behind a campaign. Recent Singapore-related petitions range from revoking someone's citizenship to returning our CPF contributions.

Which petitions have been the most, and least successful in Singapore? I analysed 85 Singapore-related petitions on Change.org, the world's largest petition platform, and copied down the number of supporters for each petition. Here are the results, correct as of today (some petitions are still ongoing):

Monday, September 29, 2014

Friday, September 26, 2014

How can I become a better footballer?

By spending more time training, of course, but should you learn to shoot and dribble better, or spend time on physical fitness, so that you can run faster?

Thursday, September 18, 2014

Will Scotland become independent?

"Polling in Scotland's independence referendum has closed, leaving campaigners and onlookers across the world waiting to learn if the country will remain in the United Kingdom or not. A Yes vote in the historic ballot would see the 307-year-old union between Scotland and the rest of the UK brought to an end.

The result is expected to go down to the wire, with polls in the last two weeks of the campaign suggesting the result is too close to call." [source]

Is the result really too close to call? Based on betting odds at Ladbrokes and Paddy Power, winning the "yes" bet gets you $16 - $20 for every dollar you put on the table. Winning the "no" bet, however, gets you a paltry $0.02.

The odds are thus overwhelmingly in favour of Scotland not becoming independent. More specifically, there is a 95% chance that Scotland will remain in the UK, and 5% probability that it will become independent.

Sunday, June 22, 2014

World Cup teams: you don't get what you pay for

Examining the market value of each country in the World Cup, i.e. the sum of each player's transfer fee in the team, against it's goal difference (as of the second match), you can see that money can't buy goals. Same thing occurs when you look at how much each country pays its coach.

Thursday, June 19, 2014

Will skipping classes lower my grades?

Students who skip lessons ought to do poorly because they simply don't get taught. But as the chart below - based on PISA scores for Singapore students - shows, students who answered "1 or 2 times" to "in the last two full weeks of school, how many times did you skip some classes?" appear to do as well as students who attended every single lesson. It seems that some moderate class skipping, perhaps combined with self-study, might not necessarily be a bad thing.

Source: PISA 2012

Thursday, June 5, 2014

Do Netizens prefer Lee Hsien Loong or Roy Ngerng?

On 15 May 2014, blogger Roy Ngerng accused Prime Minister Lee Hsien Loong of misappropriating CPF funds. The latter, in response, asked Roy to remove the post immediately, apologise, and give a written offer of damages and costs, or face legal action.
Netizens responses were, not surprisingly, mixed. For instance, Online Citizen put up a citizen statement stating that the "threat of legal action is an oppressive tool with undue chilling effects on public discourse". In contrast, Sghardtruth wrote an article titled "To the youths: Blogger Roy Ngerng is NOT your hero".
Using socialmention.com, I ran sentiment analyses on "Lee Hsien Loong" and "Roy Ngerng". Sentiment analysis measures "the attitude of a speaker or a writer with respect to some topic" (wiki). 
Here, I measured the proportion of positive, neutral, and negative mentions of "Roy Ngerng" and "Lee Hsien Loong" in social media sites like Facebook and Twitter over the past week. The data is summarised below. Here, you can see that attitudes towards PM Lee tend to be more polarised than Roy Ngerng, with a greater proportion of negative and positive views, but a smaller proportion of neutral views. 

If you were to give 1 point for every %-point proportion of positive views, 0 for neutral views, and -1 for negative views, PM Lee would garner 48% - 5% = 43% points, whereas Roy Ngerng would get 27% - 1% = 26% points. On this scale, it looks like Netizens tend to like PM Lee compared to Roy Ngerng. 
Do note, however, that this was about the individuals in general, and not specific to the Roy Ngerng issue. For example, comments about changes to Medishield Life were included for PM Lee. 

What policies will the next winning political party support? A forecast using the median voter theorem

The median voter theorem predicts that in an election, the outcome most preferred by the median voter will garner the most votes. 

Suppose views about an issue are spread out across two ends on a spectrum, "strongly agree" and "strongly disagree", with "agree", "neutral", and "disagree" in the middle. To win the most votes, the politician/party will have to take a view closest to that of the majority. If you order voters according to their views, the middle person will likely be in the densest part of the voter distribution.

Using this theorem, we can predict what views the winning party might support, assuming that they take positions with the sole strategy of winning votes. Using responses from My Singapore Conversation, I find that the median respondent took the following positions on the topics listed below:

Strongly Disagree
Strongly Agree
Pace of life is more important than career advancement

We should reduce the inflows of foreign workers

We should have a more holistic, less competitive education system

Students should learn with others of different abilities and backgrounds

We should limit individual freedom of expression to prevent social tensions

We should censor media content to protect public interest

I accept gay lifestyles

I accept same-sex marriages

The government should take more responsibility to provide for the people

We should keep taxes low even if it limits support to the needy

We should preseve green space, even at the expense of roads, housing, and public amenities

From this, the winning party is likely value a slower pace of life, both for workers and students, and have a more inclusive learning environment in schools. The party will likely have conservative attitudes towards gay marriages, and preserve green spaces. Lastly, the party is likely to preserve the status quo with regards to immigration, freedom of expression and censorship, and supporting the needy.