Thursday 21 April 2011

On Blocked Shots

In the NHL a big deal is often made about blocked shots. After watching the Caps nearly lose Brooks Laich to injury last night I wondered again why teams put such emphasis on them.  For one thing, players lack the padding to safely block such shots so they regularly incur injury from doing so. Secondly, the shots blocked are typically low percentage outside shots. Thirdly, the player takes himself out of the play when going down to block a shot. A number of times in the NYR-Washington series I've seen a player simply skate around a player who had gone down to block a shot. (These people aren't Bobby Orr in terms of their ability to spring up after blocking a shot.)  Since the NHL records this stat, I used it to do a Pearson correlation calculation between the total shots a team had blocked and points accumulated during the season:

NYI138773
TOR132385
PHI1317106
NYR130193
ATL129280
MTL127296
WSH1257107
TBL1249103
ANA124899
EDM121962
CGY120994
DAL120495
CAR120391
COL117668
BOS1172103
BUF116896
CHI114497
SJS1141105
MIN112986
FLA112572
OTT111574
CBJ111481
STL109987
PIT1082106
VAN1071117
PHX105699
LAK103298
NSH100799
DET917104
NJD87581

Unsurprisingly, to my mind, total blocked shots doesn't track at all with point scoring success, the Pearson correlation number is actually negative, -.1428. Of course, this isn't definitive proof of its ineffectiveness, no one claimed it was a key to the game and maybe the stat gathering is bad or maybe some teams block only key shots while other teams do a lot of ineffective shot blocking. Nonetheless, it remains difficult for me to see why people think this is a laudable thing for a hockey player to do.



Tuesday 19 April 2011

Tax Increases

Almost half Tea Partiers want to increase taxes on those earning over $250K/year.  More than 60% of independents do, and 75% of self declared moderates. Why in the world are the Democrats not doing a better job holding the GOP's feet to the fire on their insane "we'll fix the deficit w/o tax increases" position. This could be a no-brainer political win for them one would think. My assumption is that they're afraid to put corporate donations at risk.

ETA: Another poll in the same vein: 80%+ dislike Ryan's medicare plan.

AV Voting in Canada?

A recent post in "On Procedure and Politics" pondered the effects of AV voting in Canada.  I was intrigued by the possibility and tried to run a simulation, using data from the '08 election and 2nd choice preferences as stated in a poll as discussed in an article linked in the aforementioned post. 

Simulation: 
Using the stated second choice preferences from the survey, I attempted to roughly simulate an AV election in the following way:
  • For each riding result, consider the percentage of vote received, PVR,  of the party with the most votes. If PVR >= 50%, stop and go on to the next party.  If PVR < 50%, move to the next step.
  • Of all the candidates in the riding remaining for consideration, identify the candidate, C, with lowest percentage of votes
  • Redistribute the votes of C according to the poll preferences in the survey.  For example, if the candidate with the fewest votes represents the NDP, we'd give 56% of their votes to the Liberal candidate if the Liberals have a candidate remaining in the riding, because 56% of NDP voters identified the Liberals as their second choice in the poll.  If a particular party in the preference list of C's party has already been removed from the list or didn't run a candidate, redistribute that party's share of C's vote according to the preferences for that party.  For example, if the party/candidate with the lowest total is the NDP, 9% of their votes should go to the BQ. But if there is no BQ candidate or the BQ had been removed from consideration, we redistribute that 9% according to BQ preferences.
  • Remove C from the list of candidates in the riding.
  • Recalculate total votes, T. If 21% of NDP voters don't have a second choice, we remove those votes from the total.
  • Identify the party with the most votes after the redistribution, determine their PVR, given their new vote total and the total votes. If their PVR is >= 50%, we're done, otherwise repeat the aforementioned process but with C removed from the list of candidates.  Continue until we have a party with a PVR >= 50%.
Here are the results under that scenario (in the spreadsheet, ridings in which the AV implementation results in a change in the winning party have a "1" in the "Changed" category).


Original: New:
Cons 143 131
Lib 77 92
BQ 49 42
NDP 37 41
Ind 2 2


Note that the Conservatives lose a number of seats, enough so that a Liberal + BQ or Liberal + NDP coalition exceeds the Conservative seat total.   Also noteworthy, neither the Conservatives nor the BQ pick up seats in this scenario.  This is because relatively few people select them as their second choice.  Here is a list of ridings in which the winning party changed.


Province Riding Winning Party Recalculated Winner
New Brunswick Saint John Cons Lib
Nova Scotia West Nova Cons Lib
Nunavut Nunavut Cons Lib
Ontario Kitchener Centre Cons Lib
Ontario Kitchener--Waterloo Cons Lib
Ontario London West Cons Lib
Ontario Mississauga--Erindale Cons Lib
Ontario Oak Ridges--Markham Cons Lib
PEC Egmont Cons Lib
Quebec Ahuntsic BQ Lib
Quebec Brome--Missisquoi BQ Lib
Quebec Haute-Gaspesie… BQ Lib
Quebec Jeanne-Le Ber BQ Lib
Quebec Laval BQ Lib
Quebec Saint-Lambert BQ Lib
British Columbia Surrey North Cons NDP
Nova Scotia South Shore--St. Margaret's Cons NDP
Quebec Gatineau BQ NDP
Saskatchewan Saskatoon--Rosetown--Biggar Cons NDP

The data can be found at link.  See the "assumption2" tab.  Also, the script is easy to rerun using different assumptions about second choices and the like, so I'd be happy to try other variations in second choices, etc.

Saturday 16 April 2011

Responsibility to vs. Responsibility For

Chuck Grassley posted a tweet yesterday claiming, "Reports of Gaddafi using Cluster bombs Nato'stimidity to stop means "blood on" Nato hand for every legles kiod. That is what clusters do". This tweet: "@ By that reasoning, there's blood on your hands for each murder in DC on a night you failed to have been out crime fighting." was my clumsy attempt to respond in fewer than 141 characters. This post is my attempt to clarify what I was trying to say.

Grassley's contention that NATO has blood on their hands if kids are hurt by Gaddafi cluster bombs seems to assume the following principle: "If an agent fails to take steps to prevent an event that they may have been able to prevent, they are morally responsible for that event." I think that it's widely accepted that moral agents have an obligation to take steps to prevent undesirable events from occurring. I think the extent of one's obligation is determined by a number of factors including the need to respect autonomy of other agents, the relative costs of interceding, the anticipated negative utility of the negative action in which one is considering intervening and the likelihood of the intervention's success. (This is the sort of analysis Peter Singer alludes to, pointing out that obviously we have a strong obligation to intercede when, say, we can save a child from drowning by sacrificing our shoes.)  I don't want to subject Libyan intervention to this sort of analysis here, I simply want to note that there is, in my opinion, a very important difference that Grassley may be paving over here. Even if one can make a case that an agent has an obligation, even a strong one, to prevent X, shouldn't we distinguish between being morally responsible for X and failing to prevent X? Arguably, one can't be morally responsible for X unless one has played a fairly direct causal role in X. That's not to say one isn't morally blameworthy for failing to prevent X, but I think it remains useful to distinguish between an obligation to prevent X and being responsible for it. This distinction does, admittedly, get a bit blurry when the obligation to intercede is extremely obvious. If I won't sacrifice my shoes to rescue a drowning child, it doesn't seem odd to suggest that I'm responsible for her death to some important extent, but I think here we're simply confusing the strong responsibility to intercede with the responsibility for the death.

Wednesday 13 April 2011

The Debt Ceiling

Over on Yglesias this morning there's what appears to be a reasonable suggestion regarding the debt ceiling debate:

As long as we’re taking hostages, I don’t see what’s stopping Democratic Senators—who, after all, constitute a majority—from starting to talk about what concessions they’re planning to demand in exchange for a debt ceiling increase.
That would be the ideal negotiating framework. White House demands clean debt ceiling increase, House majority demands big spending cuts, Senate majority demands partial repeal of Bush tax cuts, and we all compromise on just doing the damn debt increase.

But there's a simple reason it won't work. One side, or one vocal and demanding subset of one side, doesn't really care if the debt ceiling is raised, just as they were eager to see the government shutdown.  Trying to negotiate in this context is like playing a game of chicken against a suicidal guy with a car accident obsession; you can't assume he shares your interest in avoiding a wreck if at all possible.

Monday 11 April 2011

The Curious Case of the Toys at Meadow Lane Park

There's a park near our house that is filled with lots of plastic outdoor toys, many of them quite expensive to buy new.  The interesting phenomenon is that they're just left there, and don't seem to get stolen, or if they do get stolen, the rate of new arrivals appears to far exceed the rate of departing toys. 




This fascinates me. I like to interpret it as evidence that communities can share without turning greedy, and even a hopeful sign that private property isn't as integral to a functioning society as we typically assume. But my panglossian take on this has suffered a blow recently. I've talked to some who deem the park's trove of toys an eyesore and argue that it's just become a de facto refuse dump for those unwilling to dispose of their old unused toys properly. I don't think it's quite as bad as all that, such toys aren't so hard to get rid of, we've had some and put them by the side of the road and had them snapped up quickly, i.e., people are perfectly happy to take such toys if they're offered up. So, I'd like to think that it really is a positive indicator of human decency and willingness to share.