JONES, J., delivered the opinion of the court.. MERRITT, J. (pp. 622-623), delivered a separate concurring opinion. NORRIS, J. (pp. 623-624), delivered a separate dissenting opinion.
*618OPINION
Defendant Reginald Coleman appeals the sentence imposed following his plea of guilty to distribution of a controlled substance (crack cocaine) in violation of 21 U.S.C. § 841(a)(1). Coleman contends that the district court erred in concluding that it lacked the- legal authority to depart downward on the ground of the government’s allegedly improper investigatory techniques. We hold that Koon v. United States, 518 U.S. 81, 116 S.Ct. 2035,135 L.Ed.2d 392 (1996), a decision of which the district court did not have the benefit at the time of the sentencing, makes clear that a trial judge cannot categorically exclude any non-prohibited factors from consideration for a downward departure. We accordingly vacate the sentence and remand for re-sentencing.
I. Facts
In December of 1994, Defendant Reginald Coleman was approached by an undercover agent for the Bureau of Alcohol Tobacco and Firearms (“ATF”). The agent, Special Agent Joseph Secrete, was conducting an investigation in which he posed as a successful businessman and approached ex-felons as they were lawfully reporting to their parole office. According to the government,- Secrete would receive a tip that certain individuals may be engaging in criminal activity who were on parole for state convictions, and whose listed addresses were not accurate. Agent Secrete would then obtain a photograph of the individual and the location where the individual reported to a parole officer. After identifying the individual, Agent Secrete would approach the individual as he was leaving his parole office. Coleman claims that Secrete would subsequently give targeted parolees a business card, and befriend such individuals by offering rides, trips, jobs and other business opportunities. Secrete would then offer to deal in illegal narcotics and/or firearms with the individual. Apparently, all of the suspects targeted for investigation were African-American.1 On five separate occasions, Coleman delivered cocaine base to Agent Secrete.
On September, 7, 1995, Coleman was indicted on five counts of distribution of a controlled substance under 21 U.S.C. § 841(a)(1). Pursuant to a Rule 11 plea agreement, Coleman pleaded guilty to two counts. The other counts were dismissed. On May 21, 1996, after his conviction, Coleman filed a motion for a downward departure arguing that his offenses were committed due to the improper investigative technique of the ATF, by targeting and inducing parolees to commit crimes and specifically targeting only African-Americans. Coleman asserted that these factors removed the case from the “heartland” of drug offenses. The district court found that Coleman’s argument was not a sentencing issue, but rather a selective prosecution issue and thus an improper legal basis for a downward departure. Consequently, the district court sentenced Coleman to a term of 100 months imprisonment, 4 years supervised release and a mandatory special assessment of $100.00. This timely appeal followed.
II. Discussion
Generally, a court’s failure to exercise ' its discretion and grant a downward departure is not reviewable. ' See, e.g., U.S. v. Landers, 39 F.3d 643, 649 (6th Cir.1994). An appellate court may only review a denial of a motion for a downward departure if the district court judge “incorrectly believed that he lacked any authority to consider defendant’s mitigating circumstances as well as the discretion to deviate from the guidelines.” Id. (citation omitted). Here, the district court believed that it lacked the authority and discretion to depart downward. The district court repeatedly stated that it believed Coleman’s motion was a selective prosecution issue, rather than an issue to be determined in a motion for a downward departure.2 J.A. at *619119-20. The district court further concluded that because Coleman was complaining only about investigatory techniques, it did not “see a legal basis for using [investigatory techniques] as a downward departure here.” J.A. at 120. Indeed, even in the passage cited by the dissent, it is clear that the district court was far more concerned with the procedural posture of the claim rather than whether there was sufficient evidence to support a downward departure, noting that even if there were hard evidence of improper investigatory techniques, it still would not be an “issue” which would entitle the defendant to a downward departure. J.A. at 120. Viewing the district court’s statements in their entirety, it is apparent that the district court believed that Coleman’s downward departure arguments could not be'brought at sentencing and that it did not have the authority and discretion to seriously - consider the claims at that time. Accordingly, we may review the district court’s decision.
A. Standard of Review
We review a district court’s belief that it lacked the authority for a downward departure under the Sentencing Guidelines under an abuse of discretion standard. Koon, 518 U.S. at 98-102, 116 S.Ct. at 2047-48. Thus, we note that although -a determination of the permissible factors a eourt may consider in departing downward under any circumstances, is a question of law and we are not required to defer on that point, the abuse of discretion standard includes review to determine whether a court was guided by an erroneous legal conclusion. Id. at 98-100, 116 S.Ct. at 2047. A district court by definition abuses its discretion when it makes an error of law. Id.
B. Investigative Techniques
During the sentencing hearing and on appeal, the government argued that the district court lacked the authority to consider a downward departure, asserting that even if Coleman had in fact established a case of selective prosecution, there was no basis for a downward departure and the government was “unaware of any legal authority ... to depart below the applicable sentencing guideline range because of the method of investigation.” Gov. Br. 13. Moreover, the government alleged that courts have repeatedly refused to allow downward departures based on governmental misconduct. The government, however, misunderstands the import of Koon. 3
A downward departure is permitted when there is a mitigating factor that has not been adequately considered in formulating the Sentencing Guidelines. 18 U.S.C. § 3553(b); see also 1997 U.S.S.G. § 5K2.0. Because the Commission “did not adequately take into account cases that are, for one reason or another ‘unusual,’” such factors will normally not be considered in the typical “heartland” of cases embodying the conduct that each guideline describes. Koon, 518 U.S. at 92-94, 116 S.Ct. at 2044. (quoting 1995 U.S.S.G. ch. 1, pt. A, intro, comment. 4(b)). A court may grant a downward departure, .then, if circumstances exist which take *620the case out of the typical “heartland” of eases embodied by the guideline. /¿.The Supreme Court, adopting a test proposed by the First Circuit, stated that a court considering a departure should inquire:
1) What features of this case, potentially, take it outside the Guidelines’ “heartland” and make of it a Special, or unusual, case? 2) Has the Commission forbidden departures based on those features? 3) If not, has the Commission encouraged departures based on those features? 4) If not, has the Commission discouraged departures based on those features?
Id. at 95, 116 S.Ct. at 2045 (citation omitted). “If a factor is unmentioned in the Guidelines, the court must, after considering the ‘structure and theory of both relevant individual guidelines and the Guidelines taken as a whole,’ decide whether it is sufficient to take the case out of the Guideline’s heartland.” Id. (citation omitted) (emphasis added).
There are a potentially infinitesimal number of factors which may warrant a departure. Koon makes clear that a court may not categorically exclude the consideration of any one factor, and that to do so would be a transgression of the policymaking authority vested in the Commission. Id. at 105-07, 116 S.Ct. at 2050. A court is strictly limited to determining merely “whether the Commission has explicitly proscribed consideration of the factor,” and if not, “the court must determine whether the factor, as occurring in the particular circumstances, takes the cases outside the heartland of the applicable Guideline.” Id. at 109, 116 S.Ct. at 2051; accord United States v. Mendoza, 121 F.3d 510, 513 (9th Cir.1997); United States v. Core, 125 F.3d 74, 76-7 (2d Cir.), cert. denied sub nom. Reyes v. United States, — U.S.-, 118 S.Ct. 735, 139 L.Ed.2d 672 (1998) (“[T]he Guidelines themselves make clear that a court should consider in every ease, not only in rare circumstances, whether a departure is appropriate” and “absent express prohibition, a sentencing court is ‘free to consider in an unusual case whether or not the factors that make it unusual ... are present in sufficient kind or degree to warrant a departure’”) (citations omitted); United States v. Brock 108 F.3d 31, 34 (4th Cir.1997) (“[T]he unmistakable teaching of Koon is that only those factors on which the Commission has forbidden reliance ... never may provide an appropriate basis for departure. All others potentially may provide a basis for departure under appropriate circumstances.”) (citations omitted); United States v. Sherpa, 97 F.3d 1239, 1244 (9th Cir.1996). The only factors which are so precluded from consideration are race, sex, national origin, creed, religion, and socio-economic status, U.S.S.G. § 5H1.10; lack of guidance as a youth, U.S.S.G. § 5H1.12; drug or alcohol depen-dancy, U.S.S.G. § 5H1.4; and economic hardship, U.S.S.G. § 5K2.12. All other factors which a defendant posits as evidence that a downward departure may be warranted must be considered by the district court utilizing the analysis described above and making a “refined assessment of the many facts bearing on the outcome, informed by its vantage point and day-to-day experience in criminal sentencing.” Koon, 518 U.S. at 98, 116 S.Ct. at 2046-47. To do otherwise, would directly contravene the express holding ofAooraand “would run afoul of one of the important concerns articulated [by that decision].” United States v. Olbres, 99 F.3d 28, 34 (1st Cir.1996). Thus, we reiterate that there are an unquantifiable number of potential departure factors, including heretofore unknown factors that have not been previously considered , by a court. Simply because a court has not directly ruled on the factor at issue does not excuse the district court from considering the factor as a potential basis for a downward departure.
Additionally, to the extent any of our prior cases have indicated that such factors as improper investigative techniques may never warrant consideration for a downward departure, we follow our sister circuits in finding that Koon overrules all such determinations. See, e.g., United States v. Brock, 108 F.3d at 35 (finding that the Fourth Circuit’s prior holding that post-offense rehabilitation can never form a proper basis for' departure has been effectively overruled by Koon); United States v. Sherpa, 97 F.3d at 1244 (finding that the Ninth Circuit’s prior holding that a judge may not at sentencing reconsider facts that have been necessarily rejected by the jury’s guilty verdict overruled by Koon).
*621Improper investigative techniques as a basis for departing downward, are . not factors considered by the Guidelines.4 Thus,- the district court-was required to examine the structure and theory of the relevant guidelines and the Guidelines as a whole to determine whether the grounds proffered by Coleman made the case sufficiently atypical to remove it from the “heartland.” Erroneously believing that it did not have the authority to consider a downward departure, the district court discounted Coleman’s request for such a- departure, and thus abused its discretion.
The government also argues that in making thé determination that a downward departure is warranted' one or niorte of the statutory sentencing goals (deterrence, incapacitation, retribution and correction) must be implicated. We reject such a narrow application of the downward departure mechanism. The government completely misreads the Seventh Gircuit case which it relies on for such a proposition. In United States v. Pullen, 89 F.3d 368 (7th Cir.), cert. denied, — U.S.--, 117 S.Ct. 706,-136 L.Ed.2d 627 (1997), the court noted that it had previously assumed that a departure from the guidelines range must be consistent with the statutory .sentencing goals of deterrence, incapacitation, retribution and correction. Id. at 370. The court went on to note, however, that “the Supreme Court has since rejected this limitation on sentencing discretion.” Id. Thus,. the court merely determined that those goals were reasons, in favor of departure, but by no means-determinative. Id. We make no finding with respect to whether such goals do in fact give additional reasons in favor of departure, .but merely note that the Sentencing Guidelines mention “nothing about requiring each potential departure factor to advance one of the specified goals.” United States v. Carter, 122 F.3d 469, 473 (7th Cir.1997) (citing Koon).
Courts have broadly interpretedAoon and considered downward departures in a number of cases in which a downward departure may not have been, -applicable previously. See, e.g., United States v. Brennick, 134 F.3d 10, 14 (1st Cir.1998) (finding defendant’s alleged intent to eventually pay withheld taxes to government could take the defendant’s case out of the heartland of tax evasion eases); United States v. Lipman, 133 F.3d 726, 730 (9th Cir.1998) (finding district courts could have the authority to consider cultural assimilation as .a basis for a downward departure); United States v. Kapitzke, 130 F.3d 820, 824 (8th Cir.1997) (affirming downward departure based on defendant’s post offense rehabilitation efforts); United States v. Brock, 108 F.3d at 35 (remanding ease for determination whether downward departure was' warranted for post-offense rehabilitation); United States v. Rioux, 97 F.3d 648, 663 (2d Cir.1996) (affirming downward departure on the basis of defendant’s kidney failure and charitable good works); United States v. Shasky, 939 F.Supp. 695 (D.Neb. 1996) (granting downward departure because defendant was homosexual police officer). The circumstances present in this' case may well justify a downward departure as well. Unlike the disparity between crack and powder cocaine which has been rejected as a sole justification for a downward departure, any disparity present in the case sub judice would not be a disparity created deliberately by the Sentencing Commission. Cf. United States v. Weaver, 126 F.3d 789, 793 (6th Cir.1997) (noting that the district court cannot rest a departure solely upon a disparity deliberately created by the Sentencing Commission that is not a result of atypical circumstances). We, however, decline to determine ourselves whether the factors alleged by Coleman are present to such a degree as to warrant a downward departure in this case. We leave that to the district court, which as noted- in Koon, is in the best position to determine -whether the case is so unusual -as to warrant a departure. See Koon, 518 U.S. at 98-100, 116 S.Ct. at 2047 (noting-that district court enjoys an “institutional advantage” over the appellate court in making such a determination).
*622III. Cocaine Disparity
Although this court has indicated in United States v. Gaines, 122 F.3d 324 (6th Cir.), cert. denied, — U.S.-, 118 S.Ct. 396, 139 L.Ed.2d 310 (1997), that the disparity between crack cocaine and powder cocaine, even coupled with the Sentencing Commission’s own belief that the disparity should be modified, is not in itself sufficient to take a crack cocaine case out of the “heartland,” each case must still be individually considered. As the Supreme Court noted, § 5K2.0 is designed to allow district courts to “consider every convicted person as an individual and every case as a unique study in the human failings that sometimes mitigate, sometimes magnify, the crime and the punishment to ensue.” Koon, 518 U.S. at 113, 116 S.Ct. at 2053. . Thus, while the disparity alone may not indicate that a crack cocaine case is outside of the “heartland,” the disparity coupled with the improper targeting and inducement of individuals to commit those crimes may well do so. Accordingly, we hold that the district court erred by failing to consider the cocaine disparity coupled with the particular circumstances of this case to determine whether the case was removed from the “heartland” of crack cocaine eases.
IV.
For the reasons set forth above, we REVERSE and REMAND the district court’s sentencing decision, for reconsideration consistent with this opinion. We note that if the district court determines that there are no factors present to such an extraordinary degree as to warrant a departure, the sentence should not be disturbed.