Conservation

Elongated Elephant

Bulte, Van Kooten

• CITES– Bans TRADE in endangered species– Reduces Demand– Should be good for elephants, etc– (Same argument for Viagra saving Rhinos)

Poaching

• Poaching model is the fishing model, but adds enforcement.– P price– E effort (poaching– B enforcement effort– X stock– F fine (punishment)

• kExp is revenue as in fishing• C(B) E is cost of poaching and increases in B,

enforcement. Costs of evading getting caught.• T E (zkEx +p) expected value of punishment

– TE is likelihood of getting cauth– Last element is the fine where z is a parameter– Notice that this term has two E’s which drives

everything

Zero Profits for Long Run

• 0 = kExP – C(B) E – TE (zkEx +p) – Zero long run profits– Gives E(P, B, …)– Point is that poaching increases in price and

decreases in enforcement.– h = kEx is harvest

Look at the Table

• CITES goes Along with

• DECREASED enforcement

• Reminiscent of Kip Viscusi’s idea of a taste for danger. (Gov makes you wear seatbelts, so you drive faster to get in your danger quota.)

Social Planner Problem

• 1 Elephant = 4.7 cows in terms of forage

• D(x) is foregone forage

• W(B) costs of enforcement

• R(x) are the existence values and tourism values

• zTh is the value of the gov’t seized ivory

• Q is total sold ivory including legal harvest and illegal

maximand

• At each time

• P(Q) Q +R +zTh –cE –D(x) – w(B)

• S.t. dx/dt = G(x) – h – y

• Assumes CITES, only a local market

With trade

• Here P(Q) is world price– Big question is how much local price is below

world price, even after otpimization.

• Now problem is linear in y, so get most rapid approach

Model is really…

• Most efficient way to harvest animals– Poach or cull

• Right number of animals

• Since CITES doesn’t prohibit gov’t from culling, it just reduces price.

Bulte and KC

• Program this up with Zambia values and they get

Payoff Slide

So

• Elephants are on their way DOWN, Cites or no.

• CITES doesn’t do that much.

• Underlying reason—strong local market, possibly driven by smuggling.

San Joaquin Kit Fox

ESA

• Endangered Species Act– Listing– Take

• Includes annoying• Applies to private land too

– Habitat Conservation Plans• Can include a whole county• E.g. each acre of toad habitat you take you have to

buy 5 acres and preserve them elsewhere

• The ESA was not thought to be radical when it was passed. Barely any debate.

• Court action and interaction with NEPA made it a very powerful tool

• The HCP element allowed negotiation and it is now just another part of doing business

ESA

• See Gardner Shogren

• Most listed animals aren’t going to recover

• There is far too little money allocated to recovery plans to make progress

• Total value of the animals would need to be improbably high for it to be right for Congress to allocate that much money

Who gets listed?

• Amy Ando sets up model where listing depends on things like “fur”

• And also depends on pressure group activity

• She records whether there was comment for or against a listing. That is her measure of pressure.

• Payoff to a group depends on the other groups actions. The more pressure the other group applies, the more beneficial it is for the group to apply pressure.

• Defines a game where the Nash non coop soln is of the form P(i) = a + bP(j) for the two groups i and j.

• comes down to lobby is a function of furriness and other groups action.

• finds that other groups action doesn’t matter

• but furriness does.

Bollworm

Pests

• Pests are un elephants.

• They are small

• We want them dead but– We don’t want to kill ourselves and everything

else killing them

Pest Control

• Cotton, veggies are a big users of pest control• Obvious problem is that pest control materials

can – Run off and kill good things– Bio accumulate and kill bigger animals

• Like ddt and birds

– Some materials cause cancer, reproductive harm and so on.

– FERPA regulates these things– Sunding, Zilberman, Siebert worked on costs of

regulation in CA

Cotton

• Livingston, Fackler

• Two pests, boll wevil and budworm

• Two controls: BT cotton and pyrethroids

• Also a refugia– Place where we don’t use control/controls

• Problem: Bugs become immune to controls.

Biology

• Assume single gene for resistance– x,X alleles for resistance/suspectibility for BT– y,Y for pyrethroids– x(t,i) proportion of allele in growing season t

and generation i. Multiple generations per season

– g is probability of xy etc

• Since each plant has two (is diploid) alleles there are 9 genotype frequencies.

• See paper for a list and their probabilities.

• Each plant is two choices from the four possible xy combos with their frequencies g.

• This makes a 9 vector of frequencies for a generation

• Pests spend some time in refugia and some in cotton.– first generation, 95% of pests in non selective

environment– then 98% of budworms in cotton– and so on.

• Different survival rates in refugia vs in sprayed/Bt cotton.

• So at end of generation, different percent of alleles in population.

• Bigger refugia, higher percent of suspectibles maintained.

Problem

• Max money

• subject to allele dynamics

• choose refugia size, how much to spray

• findings: use less sprayed refugia and less refugia all together.