Statistic showing declining crime rate in S’pore is a bogus trend

Hint: The absolute number of total crimes committed each year has been going up and down.

By September 24, 2013

In a feel good piece of news published in The Straits Times Home section yesterday, the headline screamed: “Crime rate at a 29-year-low”.

st-crime-rate-01

Oh really?

As always, statistics only tell half the story at best, but what’s worst, is the after-the-fact reasoning that the reporter uses to provide well-sounding reasons to explain the causes for this decline. Like, for example, how more security cameras have been installed and there is a more compassionate sentencing system in place.

Because what’s the ultimate stinker in this story?

Well, crime rate, in absolute terms, has been going up and down with no obvious downward trend.

And

. Don’t worry, we’ll explain.

So, to cut to the chase, here are the two fundamental problems with the statistic that crime rate is at a 29-year low.

 

1. The “per 100,000 people” basis of comparison is the most troubling aspect about the statistic.

Here is the beautiful chart that ST did up:

st-crime-rate-02

As reported: “The crime rate – the number of cases per 100,000 people – has been falling consistently since 2005, reaching a 29-year low of 581 last year. This is a dramatic drop from 1,373 in 1992.”

Okay, sounds good if you put it that way.

Well, here’s what happens when you calculate the numbers in absolute terms:

total-crimes-committed-sing

 

Plotted on a graph:
crime-rate-singapore-92-12

Well, well, what do we have here?

It looks like the total number of crimes committed dipped in 2001, increased again after that and has stabilised in recent years hovering around the 30,000-plus mark.

Something interesting was probably brewing for a few years before 2001 to push crime down in the late 90s. But what exactly, is anybody’s guess.

What’s interesting though, is that the dip in 2001 happened to be the year 9/11 took place. The theory is that the world and crime practically stood still in the face of terrorism, and it appears that the effects were also felt in Singapore.

As you can see clearly, crime rate hasn’t actually gone down that obviously.

So how do we explain the fact that the crime rate per 100,000 population has dropped drastically as claimed in the news?

.

What can we say about crime in Singapore then?

a) The decline in crime from 1998 to 2001 is palpable and significant. Whoever was police chief during that period, deserves an award.

b) The spike in 2005 compared to 2004 is significant. There were more than 6,000 more cases of crimes committed in 2005 compared to 2004.

c) From 2006 to 2012, total crimes committed has stabilised. With population booming but total crimes staying constant, it is a good thing, right?

Erm, no.

2. Quality matters as much as quantity

Ok, let’s just say hypothetically that total crimes committed have been falling overall.

But we should always remember the age old adage: Low crime doesn’t mean no crime. And quality of crimes committed matters.

Because when we talk about crime, we also need to talk about the types of crimes that have been decreasing.

For example, is Singapore better off if the total number of petty theft cases fell by 1,000 over the past 20 years but we experienced 100 more cases of robbery-murders?

If molest cases dipped but more rapes have been committed?

If shoplifting cases fell dramatically but we have sporadically more cases of white collar crimes involving millions of dollars that were siphoned off because of a – say, I don’t know – round-tripping of funds?

The point is very simple: Without a precise breakdown of the types of crimes that have been committed over the years in this article, there is simply no good basis of comparison.

Some crimes just are more severe than others.

If you consider things from the eyes of the law, rapes are definitely much worse than molest, and white collar criminals and murderers get more jail time and even caning compared to shoplifters and petty thieves.

Numbers just don’t convey the full picture.

And that the news article should provide a fuller picture by including the regular statistical breakdown of crimes provided by the police.

So what conclusion should you draw from this news story:

i. There is no story.

ii. Beware of ex post facto reasoning (by reporters) that gives you just-so narratives trying to pass off as valid reasons.

iii. Keep your door locked, because you could be next.

Top photo from here

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