Quote Originally Posted by DuncanONeil View Post
You move from the general to the specific quite quickly here. You have referred to "assumptions", yet you are doing just that in the above statement. Said assumption being that police are intrinsically suspicious of black people. No one can provide empirical evidence that such is the case. Why does the border matter or is that meant to be a lead in to the following paragraph?

Yes it is anecdotal. And as previously stated there is no empirical data. If one of four, all guilty, were searched it seems reasonable to suggest there was some trigger, yes you would like to say color, it could be as simple as being nervous, or the manner in which questions are answered, or even a general manner of presentation.


Not sure about the "level of crimes". That could mean nature or quantity. However with police located throughout the city there is no real reason to presume that criminals caught does not represent the set of criminals in general. Your issue of bias here is either poorly thought out or poorly stated. As written it presupposes a strong bias in any random sampling. In terms of the stats on crime we have at least three sets of data. Crimes committed, criminals arrested, and criminals convicted. Neither of these sets represents a random sample. They are the complete set!


While the following are in fact my words they are a compiled sets of understanding of what you wrote. Happens that my daughter dropped by and read what you had to say in this scenario. Her opinion is that your entire scenario is biased.
She feels it is important to know what type of crime occurred. And further notes that in each case that you "assume" the black is the person chased.
In the description you have the officer presented with a crime scene with two people fleeing. That act by its nature makes both parties suspicious. In every point after that you "assume" the officer chases only the black. Can you not see that as a bias on your part. I know what I would do but, the officer on the scene is most likely to focus on the closer suspect than a specific factor of that suspect. Also in such situations decisions are made in a manner and speed that determination of why, can not be made, even well after the event. I have seen video of a person fleeing from the police make a high jump onto a wall that appears to be at least five feet high, sorry I am not going to try and chase him, no matter what he looks like.
It is so easy to dissect an officers actions after the fact. But such usually totally ignores the fact that every decision, in chases, must be made in fractions of seconds.


A police force responding to a chase does not respond with a single unit. Multiple units will automatically negate your "assumption" that only the black will be chased. Also every case you posit has the non black getting away. Not only from the scene but with the crime. You really think that an accomplice caught by the police is going to take all the blame on themselves and let someone else walk free?
Your standards on data set here are the same standards that justified a lot of discriminatory laws, and pointed to studies that showed blacks were less intelligent then whites and hence needed to be treated differently, for their own good. The particular data in this case was data showing that blacks scored lower than whites on IQ tests. In fact this data was biased because it contained cultural references familiar to whites of the day but less common among blacks (in particular nursery rhymes). By accepting that data as accurate and using it to inform policy many problems were created.

Furthermore, my claims of potential for bias are based on a long history of bias and racial profiling in many police forces around the country. This was part of police culture for a long time, leading to riots in several cities and other such problems. I find it hard to believe that this behaviour vanishes the second we find it no longer appropriate. In my own city one of our former chiefs of police spoke out in favor of racial profiling, saying that it lead to more arrests and convictions. I don't have the data to dispute whether racial profiling leads to more arrests or convictions, but even assuming this claim is true, the fact is it leads to more arrests and convictions of non-whites.

So given that the police use methods (Racial Profiling for instance) that they argue are effective and result in higher arrest rates and higher conviction rates, but work against specific minorities, why should I believe the police have an equal chance of catching a white person as catching a black person if they both commit the same crime.

Even if racial profiling is not in use, this assumption could still be problematic.

Consider for instance a border security officer who processes vehicles. The person is required to search and suspicious vehicles. They happen to dislike rap music and think it is associated with gang activity, and hence search every vehicle of someone wearing rap attire.

To simplify the data lets assume that 40% of blacks are wearing rap related attire and 10% of whites are. Furthermore lets assume that an equal number of whites and blacks are carrying drugs across the border, and that the attire of the individual is independent of whether or not they carry drugs.

Over the long run this security officer will catch 4 black people for every white person even though they aren't being racist, and even though equal numbers of blacks and whites are committing crimes.

I'd argue the onus is on you to show the data actually shows what you claim it shows, given that I've presented both a plausible way in which the data can be inaccurate which you are unable to account for and a history showing that the bias has been present in the past.

The statement in your argument I have the most problem with is this: "However with police located throughout the city there is no real reason to presume that criminals caught does not represent the set of criminals in general.".

There are a lot of reasons to believe the set of criminals caught doesn't represent the set of criminals in general. For starters different types of crimes are caught at different rates, so if whites are committing more of a certain type of crime that gets caught less (say white collar crime) and blacks are committing one of the crimes (say armed robbery) that gets caught at a higher rate then there are problems in the data. Even if you focus in on a particular crime, you introduce all sorts of new biases, in particular the choice of crime to focus on (given that different crimes have different race data).

Lastly, even if you manage to reduce the data to a single crime without introducing bias, you still don't have evidence showing the arrest data mirrors the committed crimes set. Racial profiling is effective at catching criminals, but results in a higher rate of catching blacks than of catching whites. If police are using methods that are better at catching specific races then that introduces bias in the data. As argued above, they have historically used such methods so the onus is on you to prove they aren't using them anymore.